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Transplanting Success of Balled-And-Burlapped Versus Bare-Root Trees in the Urban Landscape

Authors:

Abstract

In this study, 40-mm-caliper (1.5-in.) balled- and-burlapped (B&B) and bare-root (BR) hackberry (Celtis occidentalis), American hophornbeam (Ostrya virginiana), and swamp white oak (Quercus bicolor) were paired and planted on sites throughout the city of Ithaca, New York. Half of the trees were planted in fall, half in spring. BR trees received a hydrogel root dip at the nurs- ery to prevent post-harvest root desiccation. Survival rates were excellent for all treatment combinations except spring-planted BR hophornbeam, which experienced 50% mortality. Growth measurements were taken in August of the first and second growing seasons. First-year results showed many significant differences between treatments. By the end of the second growing season, however, very few significant differences in growth responses between treatments persisted. During the first growing season, fall- planted BR hackberry grew better than fall-planted B&B hackberry. Growth on spring-planted hackberry was bet- ter on B&B trees. Fall-planted hop-hornbeam responded equally well B&B and BR, but spring-planted hophornbeam grew better B&B. Swamp white oak grew somewhat better B&B than BR, regardless of season. Both B&B and BR swamp white oak planted in fall grew some- what better than their spring-planted counterparts. A separate study on swamp white oak looked at the impact of withholding irrigation on spring-planted, paired B&B and BR trees. B&B and BR swamp white oak trees per- formed equally well after two growing seasons character- ized by drought.
298Buckstrup and Bassuk: Bare-Root vs. B&B Transplanting
TRANSPLANTING SUCCESS OF BALLED-AND-
BURLAPPED VERSUS BARE-ROOT TREES IN THE
URBAN LANDSCAPE
by Michelle
J.
Buckstrup1 and Nina L. Bassuk2
Abstract. In this study, 40-mm-caliper (1.5-in.) balled-
and-burlapped (B&B) and bare-root (BR) hackberry
(Cdtis occidentalis), American hophornbeam (Ostrya
virginiana),
and swamp white oak
(Quercus bicolor)
were
paired and planted on sites throughout the city of Ithaca,
New York. Half of the trees were planted in fall, half in
spring. BR trees received a hydrogel root dip at the nurs-
ery to prevent post-harvest root desiccation. Survival rates
were excellent for all treatment combinations except
spring-planted BR hophornbeam, which experienced 50%
mortality. Growth measurements were taken in August of
the first and second growing seasons. First-year results
showed many significant differences between treatments.
By the end of the second growing season, however, very
few significant differences in growth responses between
treatments persisted. During the first growing season, fall-
planted BR hackberry grew better than fall-planted B&B
hackberry. Growth on spring-planted hackberry was bet-
ter on B&B trees. Fall-planted hop-hornbeam responded
equally well B&B and BR, but spring-planted
hophornbeam grew better B&B. Swamp white oak grew
somewhat better B&B than BR, regardless of season. Both
B&B and BR swamp white oak planted in fall grew some-
what better than their spring-planted counterparts. A
separate study on swamp white oak looked at the impact
of withholding irrigation on spring-planted, paired B&B
and BR trees. B&B and BR swamp white oak trees per-
formed equally well after two growing seasons character-
ized by drought.
Key Words. Transplanting; balled and burlapped;
B&B;
bare root; season; fall planting; spring planting; hack-
berry (Cdtis
occidentalis);
American hophornbeam (Ostrya
virginiana);
swamp white oak
(Quercus
bicolor);
hydrogel.
Bare-root (BR) transplanting historically has been
considered by many in the landscape industry in-
cluding arborists, to be higher risk than B&B trans-
planting (Kozlowski and Davies 1975; Cool 1976;
Pirone et al. 1988). Post-planting stress caused by
desiccation of roots during post-harvest handling is
thought to be the major cause of poor establishment
for BR trees.
Few studies have been done to compare the im-
pact of B&B and BR production methods on trans-
planting success in the urban environment. Heisler
et al. (1982) planted B&B and BR red maple (Acer
rubrum 'October Glory') and green ash (Fraxinus
pennsylvanica
'Marshall Seedless') in parking-lot tree
pits.
After two growing seasons, the authors found
that both BR red maples and green ashes generally
grew better than their B&B counterparts.
The transplanting performance of trees dug and
moved by tree spade is comparable to the transplant-
ing performance of B&B trees (Gilman 1997). Thus,
two urban studies comparing BR and tree spade
transplanting are considered here. Cool (1976)
found that over a ten-year period the average mortal-
ity for BR trees was 41% but less than 5% for tree
spade trees. He determined that 2.5 surviving tree
spade trees could be planted for the same expense as
one surviving BR tree. Vanstone and Ronald (1981)
compared BR and tree spade-harvested green ash
(Fraxinus pennsylvanica
'Patmore'), black ash
(F.
nigra
'Fallgold'), hackberry (Cdtis
occidentalis),
and Amur
cherry
(Prunus
maackii).
In the first growing season,
all tree spade trees except Amur cherry showed sig-
nificantly greater shoot extension and leaf area than
their BR counterparts. After two seasons, however,
differences in growth between BR and B&B trees of
all four species were not significant.
Most studies comparing production methods
took place in nonurban nursery and test field situa-
tions.
Magley and Struve (1983) compared 7-to 15-
cm-caliper (3- to
6-in.)
BR and tree spade-dug pin
oaks
(Quercus
palustris).
Shoot extension and leaf ex-
pansion were significantly greater for trees trans-
planted by tree spade than for.BR trees. A study by
Hensley (1993) compared the impact of B&B, BR,
and fabric-bag production methods on the height,
caliper, and dry root weight of 2.5-cm-caliper (1-in.)
green ash trees. The author found no significant dif-
ference among the three production methods in tree
Journal of Arboriculture 26(6): November 2000299
height, stem diameter, or dry root weight at any time
during the four-year study.
Spring is advocated by Pirone et al. (1988) and
others as the best time to transplant BR trees, without
regard to species. Nurseries and authors of street tree
manuals publish lists of fall transplanting hazards
(Bailey Nurseries 1999; Northern Nurseries 1999;
Princeton Nurseries 1999) or trees best planted in
spring (Schein 1993; Watson and Himelick 1997).
These recommendations frequently are based on an-
ecdotal experience and do not distinguish between
production methods. Several research studies have in-
dicated transplanting success can actually be greater
in fall, depending on
species.
In Ithaca, New
York,
BR
green ash and tree lilac (Syringa
reticulata)
trans-
planted successfully in fall (Harris and Bassuk 1994).
B&B fringetree (Chionanthus virginicus) planted in
Blacksburg, Virginia, transplanted more successfully
in fall than spring (Harris et al. 1996). A study of
BR
littleleaf linden (Tilia
cordata)
by Witherspoon and
Lumis (1986) looked at root regeneration of three
digging-planting time combinations in Ontario,
Canada. The fall-dug, fall-planted trees had the great-
est new root growth, which suggests that fall is the
best time to transplant this species.
Some studies suggest that planting at other times
of year is preferable, depending on species. For ex-
ample, Watson et al. (1986) looked at eight species
of shade trees transplanted by tree spade in Illinois
in the months of March,
May,
July, or October. Shoot
extension was measured for five years after trans-
planting. Based on their results, the authors could
not make general recommendations about fall versus
spring transplanting. For several of the species, July
transplanting provided the best results when ad-
equate soil moisture was maintained.
The purpose of our study was to compare fall and
spring B&B and BR transplanting of three street tree
species in the urban environment. Hackberry
(Celtis
ocddentalis),
American hophombeam
(Ostrya
virgini-
ana),
and swamp white oak
(Quercus bicolor)
were se-
lected for several reasons. Anecdotally, they are
considered by the industry to be difficult to transplant
(variably difficult in the case of hackberry), yet all had
shown promise as street trees in Ithaca, New York.
Furthermore, little research had been conducted with
these species. It was hoped that these comparisons
would lead to recommendations for the best season
and production method for transplanting each spe-
cies.
A separate study, to test the validity of the com-
monly held opinion that
B&B
trees have an advantage
over BR trees in coping with drought stress, would
involve withholding irrigation from paired B&B and
BR
swamp white oak trees.
MATERIALS AND METHODS
Plant Material
Ten each of the following three species were harvested
balled and burlapped (B&B) on October 23, 1997,
from the Chenango gravelly loam of Schichtel's Nurs-
ery, Springville, New York, United States: hackberry,
American hophombeam, and swamp white oak. In
addition to the B&B trees, ten each of the same spe-
cies were harvested BR on October 29, 1997. In
spring 1998, hackberry and hophombeam were har-
vested in the same manner and in the same numbers,
but an extra ten B&B and ten BR swamp white oak
were dug for use in the related experiment comparing
effects of drought stress on B&B and BR trees. Due to
weather and work scheduling factors, the spring B&B
hackberry trees were harvested at different times rang-
ing from March 16 to April 3, 1998. All spring B&B
hophombeam were harvested on March 11, 1998,
and all spring B&B swamp white oak were harvested
on March 6, 1998. Spring BR trees were harvested on
dates as follows: hackberry, April 13, 1998;
hophombeam, April 12, 1998; swamp white oak,
April 11, 1998. All hophombeam in the study were
dug from the same nursery block, as were all swamp
white oak. Among hackberry, all but seven spring
B&B trees were dug from the same nursery block. All
trees were dormant when dug, with the exception of
spring hophombeam that, due to unusually warm
weather, started to break bud just prior to harvest.
Fall BR trees were dug, dipped, and transported
on October 29, 1997. B&B trees were also trans-
ported on October 29. Due to unusually warm
weather, spring BR trees were dug four to six days
before they were dipped and picked up on April 17,
1999.
During the holding period before pickup, they
were stored in a cool, shaded garage and watered
every other day. Spring B&B trees were delivered to
the Ithaca municipal nursery on April 13, 1998.
Trees of 40 mm (1.5 in.) caliper were dug accord-
ing to ANSI Z60.1-1996 standards (American Asso-
ciation of Nurserymen 1996). B&B trees were dug
300Buckstrup and Bassuk: Bare-Root vs. B&B Transplanting
with a Vermeer tree spade, and root balls were put
into wire baskets lined with natural burlap. Root-ball
diameters met or exceeded the standard of 51 cm (20
in.) for a 40-mm-caliper (1.5 in.) tree. Hophornbeam
and hackberry root balls were 51 cm (20 in.) in diam-
eter and swamp white oak root balls were 61 cm (24
in.) in diameter.
BR
trees were dug with a U-blade and
exceeded the ANSI minimum root spread of 56 cm
(22 in.) for 40-mm-caliper trees. All trees conformed
to ANSI standards for appropriate height-to-caliper
relationship.
Dipping Procedure for BR Trees
All BR trees were dipped in a hydrogel slurry at the
nursery immediately prior to transport. Using a
method modified from Haug (1996), approximately
15 oz (445 mL) of Soil Moist Fines (particles sized
700 \i or less) hydrogel was added for every 25 gal
(95 L) of water, mixed in a 100-gal (380-L) plastic
container, then left to hydrate for ten to fifteen min-
utes.
Tree roots were dipped in the slurry and imme-
diately slipped into large, pleated plastic bags. Bags
were knotted around the trunk to hold in moisture,
and trees were stacked gently in the bed of a dump
truck. The truck bed was securely tarped for trans-
port and upon arrival, BR trees were stored in a cool,
shaded shed until planted two to five days later.
Planting Procedure
Seventy sites throughout the city of Ithaca were se-
lected for pairing a total of 140 B&B and BR trees in
tree lawns. At each site, one B&B and one BR tree of
the same species and transplanting season were
planted. B&B trees and their BR counterparts were
planted in close proximity—usually, 4.5 to 6.0 m
(15 to 20 ft)—thereby ensuring similar soil type and
microclimate (Figure 1). Tree lawn width varied
from 1.5 m (5 ft) in downtown areas to greater than
4.5 m (15 ft) in residential areas.
Fall trees were planted October 31, 1997, and
November 3 and 4, 1997. Spring trees were planted
April 20 through 22, 1998. BR planting holes were
dug with shovels; B&B holes were dug with a back-
hoe.
Regardless of digging equipment, holes were
comparable in width, and glazing of the sides of the
planting hole was not observed. Turf was removed
and holes were made at least as wide as the spread of
the root system. Trees were planted so that the be-
;,'' 'Kit''
Figure 1. Paired B&B and bare-root Ostrya
virginiana on city street representing typical spac-
ing in this study. Tree closest to viewer is B&B;
tree farther back is bare root.
ginning of the root flare was just visible at grade. All
trees were watered in immediately after planting and
received 5 to 10 cm (2 to 4 in.) of wood-chip mulch
in a 46-cm (18-in.) radius from the trunk. With only
two exceptions, trees were not staked. Starting in the
spring of 1998, all trees in the main study received
20-gal (75-L) Treegator® drip irrigation bags that
were filled at the discretion of the city of Ithaca for-
estry crew, usually once a week during dry stretches.
All 20 swamp white oak trees in the irrigation-
withheld study were lined out in B&B-BR pairs along
one street to minimize microclimatic and soil differ-
ences between sites. They were watered only once at
planting and thereafter received no irrigation.
Journal of Arboriculture 26(6): November 2000301
Data Collection
In August 1998, when terminal buds had set, four
growth responses were measured on all trees. First,
shoot extension was measured to the nearest half
centimeter on three mid-canopy, full-sun terminal
shoots per tree, and the mean was calculated. Sec-
ond, dieback was also measured on three mid-
canopy terminal shoots per tree, and the mean was
calculated. We devised a third visual index called
"leaf canopy rating" to give an approximation of the
fullness of the canopy relative to its branch density
Leaf canopy complemented the other measurements
by taking into account the extent of dieback and bud
break failure within the canopy. For leaf canopy rat-
ing, a percentage scale in increments of ten was
used, with 100% corresponding to a tree that had
fully leafed out and had no measurable dieback
within the canopy. Figure 2 gives examples of this
rating on hackberry. Finally, average area per leaf was
calculated from a sample of half of the trees. Ten
mid-canopy, representative leaves per tree were mea-
sured with a LI-COR LI-3100 leaf area meter. The
mean area in square centimeters per leaf was then
calculated. The same measurements were repeated in
August 1999 to give second-year growth data. Soil
samples weighing at least 50 g (1.8 oz) were taken
from the majority of the sites by extracting soil
15 cm (6 in.) below turf roots with a shovel. Samples
were dried and analyzed for pH and gravel, and for
sand, silt and clay fractions.
Statistical Analysis
The statistical software package SPSS 9.0 was used to
analyze the data. Means of paired B&B and BR trees
planted within the same season were analyzed using
paired t-tests. Means for both root types between
Figure 2. A visual "leaf canopy rating" was devised to capture the fullness of
the canopy relative to its branch structure. The hackberry on the left rated
60%;
the hackberry on the right rated 90%.
302Buckstrup and Bassuk: Bare-Root vs. B&B Transplanting
seasons were analyzed using independent samples t-
tests.
Because leaf canopy ratings were recorded as
percentages and their mean distribution was not nor-
mal, leaf canopy means were analyzed using the
nonparametric Wilcoxon signed rank test (for com-
paring within season) and the Mann-Whitney U-test
(for comparing between season). Analysis of covari-
ance was used to look at the potential influence of soil
texture, specifically the sand fraction, on the results.
RESULTS
Survival rates were excellent for all treatment combi-
nations except spring-planted BR hophornbeam
(Table 1). Four trees were lost to vandalism or theft
and were thus excluded from consideration in this
study.
Comparing Production Methods
Hackberry. In year one, fall-planted BR hackberry
outperformed fall-planted B&B hackberry. Mean
area per leaf on BR hackberry was significantly (P <
.05) greater (54% larger) than on B&B trees. In year
two,
fall-planted B&B and BR hackberry showed no
significant differences in any of the responses.
For spring-planted hackberry, B&B trees fared bet-
ter than BR in year one. Shoot extension, leaf canopy,
and leaf area were all greater for
B&B
trees than for
BR
trees,
though only leaf canopy was significant (122%
larger).
Dieback on spring-planted BR trees was sig-
nificantly greater (125% larger) than on spring B&B
trees.
In year two, the same trends were seen but were
not significant except for leaf canopy (Table 2).
Hophornbeam. In both the first and second grow-
ing seasons, fall-planted B&B and BR hophornbeam
showed no difference in growth responses. Spring-
planted trees, however, showed a significant trend in
favor of
B&B
production in the first year. Shoot exten-
sion, leaf canopy, and leaf area were all significantly
greater (236%, 67%, and 216%, respectively) for B&B
trees than for BR trees. In year two, only leaf area was
significantly greater (Table 3).
Swamp white oak. First-year measurements on
fall-planted swamp white oak suggested a small B&B
advantage over
BR.
Shoot extension was not statistically
different, but leaf canopy and leaf area were signifi-
cantly greater for B&B trees. In the second year, how-
ever, there was no difference between growth responses
of fall-planted B&B and BR swamp white oak. Spring-
planted trees measured in the first year showed some-
Table 1. Survival rates for three species after first
and second growing seasons. Season listed refers
to season of planting. Percent survival is followed
in parentheses by total number of trees of given
treatment.
Species and
production method
Hackberry, B&B
Hackberry, BR
Hophornbeam, B&B
Hophornbeam, BR
Swamp white oak, B&B
Swamp white oak, BR
Fall
Year 1
100 (9)
100 (9)
100 (10)
100 (10)
100 (10)
100 (10)
Spring
Year 1
100 (10)
100 (10)
100 (8)
100 (10)
100 (20)
100 (20)
Fall
Year 2
89(9)
100 (9)
100 (10)
100 (10)
100 (10)
100 (10)
Spring
Year 2
100 (10)
90 (10)
100 (8)
50 (10)
100 (20)
95 (20)
Table 2. Comparing production method for hack-
berry within season of planting. Means read across
the table are pairwise comparisons. Shoot exten-
sion (SE) given in centimeters, leaf canopy rating
(LC) given in %, leaf area (LA) given in square
centimeters, and dieback (DB) in centimeters.
Year and
season
Year
I
Fall
Spring
Year
2
Fall
Spring
B&B
SE
8.2
11.6
17.7
13.2
BR
SE
15.2
8.9
17.4
10.3
B&B
LC
55
80*
84
80*
BR
LC
65
36
87
71
B&B
LA
12.5
14.9
31.0
28.1
BR
LA
19.2*
11.7
27.8
22.2
B&B
DB
14.3
5.1
.31
1.0
BR
DB
17.8
11.5*
.00
1.3
^Indicates significant difference (P < .05) between B&B and BR means. For
leaf canopy ratings, significance was determined by the nonparametric
Wilcoxon signed rank test.
Table 3. Comparing production method for hop-
hornbeam within season of planting. Means read
across the table are pairwise comparisons. Shoot
extension (SE) given in centimeters, leaf canopy rat-
ing (LC) given in %, leaf area (LA) given in square
centimeters, and dieback (DB) in centimeters.
Year and
season
Year
I
Fall
Spring
Year
2
Fall
Spring
B&B
SE
5.1
8.1*
8.6
12.7
BR
SE
5.2
2.4
7.1
8.1
B&B
LC
88
97*
83
97
BR
LC
86
58
87
83
B&B
LA
10.7
11.7*
26.1
22.6*
BR
LA
8.7
3.7
19.6
17.6
B&B
DB
.30
.23
.00
.00
BR
DB
.00
3.3
.00
.00
"Indicates significant difference (P < .05) between B&B and
BR
means. For
leaf canopy ratings, significance was determined by the nonparametric
Wiicoxon signed rank test.
Journal of Arboriculture 26(6): November 2000
303
what larger growth means
for
B&B trees than
for
BR
trees,
but
only leaf canopy
was
significantly greater.
Second-year data showed
no
difference between B&B
and
BR
swamp white oak planted in spring (Table 4).
Comparing Season of Transplanting
Hackberry. Spring-planted B&B hackberry showed
trends towards greater growth than fall-planted B&B
trees,
though only leaf canopy (43% larger) was sig-
nificantly greater.
In
the second year, however, there
were no differences
in
growth responses between fall
and spring B&B trees.
BR hackberry grew better when planted
in
fall.
In
year one, mean leaf canopy and leaf area were signifi-
cantly greater (81%
and
64%, respectively)
on
fall-
planted BR trees than
on
spring-planted BR trees.
In
year two,
the
same trends persisted
in
favor
of
plant-
ing
BR
trees
in
fall, though only leaf canopy (21%
larger) was significantly greater (Table 5).
Hophornbeam. Growth means were higher
for
spring-planted B&B trees than
for
fall-planted B&B
trees,
though only leaf canopy
was
significantly
greater. In the second year, differences noted were not
statistically significant.
In
the
first year, fall-planted
BR
hophornbeam
clearly performed better than those planted
in
spring.
All four response means were significant: Fall-planted
trees had 73% larger shoot extension, 46% larger leaf
canopy, 135% larger leaf area,
and no
dieback com-
pared
to
a mean dieback of 4.7 cm (1.8 in.) on spring
trees.
In
year
two, 50% of the
spring-planted
BR
hophornbeam died. Yet of those that survived, no sig-
nificant difference between spring trees and their fall-
planted BR counterparts was noted (Table 6).
Swamp white
oak. In the
first year, some
evi-
dence suggested that both B&B and BR swamp white
oak fared better
in
fall than spring. Fall-planted B&B
trees had significantly greater leaf canopy and leaf area
than their spring
B&B
counterparts.
Fall-planted
BR
trees
had
significantly greater
shoot extension (39% larger)
and
leaf canopy (13%
larger) than their spring BR counterparts.
In the
sec-
ond year,
no
statistically significant differences were
noted (Table
7).
Comparing Irrigation-Withheld Trees
Ten B&B
and ten
BR swamp white
oak
trees were
planted
in
pairs
in
spring. Trees were watered
in at
planting
but
received
no
subsequent irrigation.
In
Table 4. Comparing production method for swamp
white
oak
within season
of
planting. Means read
across
the
table
are
pairwise comparisons. Shoot
extension (SE) given in centimeters, leaf canopy rat-
ing (LC) given
in
%, leaf area (LA) given
in
square
centimeters, and dieback (DB) in centimeters.
Year
and
season
Year
I
Fall
Spring
Year
2
Fall
Spring
B&B
SE
12.4
8.8
6.9
4.9
BR
SE
9.7
7.0
6.9
4.4
B&B
LC
98*
91*
98
94
BR
LC
90
80
96
91
B&B
LA
35.1*
22.4
59.7
51.3
BR
LA
24.0
21.4
57.0
56.0
B&B
DB
.00
.00
.00
.00
BR
DB
.03
.75
.00
.00
indicates significant difference (P < .05) between B&B and BR means.
For
leaf canopy ratings, significance was determined by the nonparametric
Wilcoxon signed rank test.
Table
5.
Comparing transplanting season for hack-
berry. Means read across
the
table
are
pairwise
comparisons. Shoot extension (SE) given
in
centi-
meters, leaf canopy rating
(LC)
given
in %,
leaf
area (LA) given in square centimeters, and dieback
(DB)
in
centimeters.
Year
and
Fall
Spr.
Fall
Spr.
Fall
Spr.
Fall
Spr.
method
SE SE LC LC LA LA DB DB
Yearl
B&B
BR
Year
2
B&B
BR
8.5
14.8
16.8
15.6
11.6
8.9
14.2
10.2
56
65*
84
86*
80*
36
81
71
12.5
19.2*
31.0
28.0
14.9
11.7
28.0
22.0
14
17
.1*
.0
.27
.13
5
11
1
.1
.5
.90
.3*
indicates significant difference
(P
< .05) between fall and spring means.
For leaf canopy ratings, significance was determined by the nonparametric
Mann-Whitney U-test.
Table
6.
Comparing transplanting season for hop-
hornbeam. Means read across
the
table
are
pair-
wise comparisons. Shoot extension (SE) given
in
centimeters, leaf canopy rating (LC) given
in %,
leaf area (LA) given in square centimeters, and die-
back (DB)
in
centimeters.
Year
and
method
Yearl
B&B
BR
Year
2
B&B
BR
Fall
SE
5.1
5.2*
8.6
7.1
Spr.
SE
8.1
3.0
12.6
9.3
Fall
LC
88
86*
83
87
Spr.
LC
97*
59
90
76
Fall
LA
10.7
8.7*
26,0
20.0
Spr.
LA
11.7
3.7
23.0
18.0
Fall
DB
.30
.00
.00
.00
Spr.
DB
.23
4.7*
.38
.00
""Indicates significant difference (P < .05) between fall and spring means,
For leaf canopy ratings, significance was determined
by
the nonparametric
Mann-Whitney U-test.
304Buckstrup
and
Bassuk: Bare-Root vs. B&B Transplanting
Table
7.
Comparing transplanting season
for
swamp white
oak.
Means read across
the
table
are
pairwise comparisons. Shoot extension (SE) given
in centimeters, leaf canopy rating (LC) given
in
%,
leaf
area
(LA) given
in
square centimeters, and die-
back (DB)
in
centimeters.
Year
and
method
Yearl
B&B
BR
Year
2
B&B
BR
Fall
SE
12.4
9.7*
6.9
6.9
Spr.
SE
8.8
7.0
4.9
4.4
Fall
LC
98*
90*
98
96
Spr.
LC
91
80
94
91
Fall
LA
35.1*
24.0
60.0
57.0
Spr.
LA
22.4
21.4
51.0
56.0
Fall
DB
.00
.03
.00
.00
Spr.
DB
.00
.75
.00
.00
indicates significant difference (P < .05) between fall
and
spring means.
For leaf canopy ratings, significance was determined
by
the nonparametric
Mann-Whitney U-test.
Table
8.
Comparing
B&B to
bare root swamp
white oak
in the
irrigation-withheld study. Means
read across
the
table
are
pairwise comparisons.
Shoot extension
(SE)
given
in
centimeters, leaf
canopy rating (LC) given
in
%,
leaf area (LA) given
in square centimeters,
and
dieback (DB)
in
centi-
meters.
Year
Year
1
Year
2
B&B
SE
7.1
6.2
BR
SE
8.0
6.3
B&B
LC
88*
86
BR
LC
82
91
B&B
LA
27.2*
53.1
BR
LA
19.9
59.6
B&B
DB
.30
.19
BR
DB
.68
.00
•Indicates significant difference (P <
.05)
between
B&rB
and
BR
means.
For
leaf canopy ratings, significance was determined
by
the nonparametric
Wilcoxon signed rank test.
year
one,
mean leaf canopy
and
leaf area were
sig-
nificantly greater
on the B&B
trees
(7% and 37%,
respectively).
In
year two, there were
no
significant
differences between B&B
and
BR trees (Table
8).
Soil Sampling Results
Results showed
a
surprisingly uniform soil texture
and
pH
across sites. Most sites were characterized
by
loam, gravelly loam, silt loam,
or
gravelly silt loam
soils;
two-thirds
of
the sites
had
more than 50%
com-
bined sand
and
gravel fraction.
The
majority
of the
sites were
in the 6.6 to 7.5 pH
range.
The
covariate
analysis
on
sand fraction addressed
the
concern that
some sites might
be
drier than others.
The
analysis
revealed
no
significant effects
of
this variable
on the
growth responses
for any of the
trees
in
either year
(data
not
shown).
DISCUSSION
Hackberry
In this study, fall-planted BR hackberry grew just
as
well
as
fall-planted B&B hackberry. Furthermore, fall-
planted
BR
trees grew better than spring-planted'
ones.
The success
of
fall-planted BR hackberry
in
this
study confirms some industry opinions
and
contra-
dicts others. Hightshoe (1988) recommends
BR
fall
planting of hackberry
if
done "with care." Berrang and
Karnosky (1983) say that hackberry can be planted
in
fall
or
spring. Bailey nurseries (1999) suggests avoid-
ing planting hackberry
in
late fall, and Princeton nurs-
eries (1999) lists hackberry
as
"very risky"
to
transplant, BR
or
B&B,
in
fall.
Fall planting comes with myriad potential advan-
tages from which
the
BR hackberry
in
this study may
have benefited.
A
previous study established that
root growth
in
Ithaca ceases around
the end of
Ocu>
ber (Harris
and
Bassuk 1994). Trees
in
this study
were planted
in
late October
and
early November;
therefore, fall root growth was unlikely
to be one of
those advantages. However,
the
physiological
pro-
cesses
in
roots that precede root growth might
get
underway
in
fall, giving fall-planted trees
an
advan-
tage
in the
next growing season (Harris
et
al. 1996).
Another benefit
of
fall planting
is
reduced water
stress.
Transpirational demand
of
leaves
and
shoots
is lower
in
fall than spring because ambient tempera-
tures are cooler, days are shorter, shoot extension has
ceased,
and
plant cells have lignified (Good
and
Corell 1982). Roots
of
fall-transplanted trees
are in
place longer before new spring shoot growth begins,
and root-to-soil contact
is
improved
as a
result.
The
roots
of
spring-harvested trees,
by
contrast,
are sev-
ered shortly before shoot growth begins
in
spring.
Hinesley (1986) suggests that fall-planted trees
may
do better because spring harvests interfere with
the
production
of
root-produced hormones necessary
for good shoot extension.
Spring-planted B&B hackberry grew better than
their spring-planted
BR
counterparts. This finding
conforms
to the
conventional thinking that
B&B
transplanting
is
less stressful
and
leads
to
faster
es-
tablishment than
BR
planting (Pirone
et al.
1988).
This outcome validates
the
recommendation
by
Hightshoe (1988) that hackberry
be
planted B&B
in
spring. However,
the
result
in
this study differs from
that
of
Magley
and
Struve (1983)
who
found that
spring-planted
pin
oak performed equally well when
Journal of Arboriculture 26(6): November 2000305
harvested by tree spade (equivalent in most respects
to B&B) or BR. The result in this study also differs
from Vanstone and Ronald (1981) who found that
spring-dug BR hackberry actually surpassed tree
spade hackberry in growth by the second year. A
four-day holding period before dipping might have
put the spring BR hackberry in this study at a disad-
vantage relative to the B&B trees. Whereas fall BR
hackberry were dipped and transported the same
day they were dug, spring trees were dipped and
transported four days after they were dug. A shorter
holding period might have resulted in less root des-
iccation and a growth response more comparable to
that of the B&B trees.
When compared across seasons, B&B and
BR
hack-
berry grew equally well in fall and spring. This contra-
dicts Dirr (1998), Princeton nurseries (1999), Bailey
nurseries (1999), and others who specify spring plant-
ing or warn against fall planting.
Hophornbeam
In this study, fall-planted B&B and fall-planted BR
hophornbeam grew equally well. Both fall-planted
B&B and BR hophornbeam grew equally well as
their spring-planted counterparts. Significant differ-
ences were present only when comparing spring-
planted trees; then, B&B outperformed BR. It is
possible that spring-planted BR hophornbeam
would have performed just as well if not subject to
early bud break and a five-day holding period before
dipping. Nonetheless, based on the results of this
study, if one must plant in spring, B&B appears to be
the better choice. If fall-planting is an option, the
results of this study suggest that BR is just as good.
This finding contradicts many sources recommending
spring planting for hophornbeam (Berrang and
Karnosky 1983; Hightshoe 1988; Schein 1993;
Watson and Himelick 1997; Dirr 1998) or that cau-
tion against fall planting (Bailey Nurseries 1999;
Princeton Nurseries 1999). This contradiction may be
explained by the fact that the BR trees in this study
had the benefit of the hydrogel root-dip protocol.
Swamp White Oak
Comparison of paired B&B and
BR
swamp white oak
in both fall and spring showed no advantage to ei-
ther production method. Oaks generally are consid-
ered fall transplanting hazards (Bailey Nurseries
1999;
Northern Nurseries 1999; Princeton Nurseries
1999) or are recommended for spring planting
(Berrang and Karnosky 1983; Schein 1993; Watson
and Himelick 1997). By year two of this study,
growth of swamp white oak showed no significant
difference between fall and spring planting, only a
mild trend in favor of fall.
Comparing First and Second
Growing Seasons
In the first year, there were significant differences in
growth responses between many treatment combina-
tions of season, species, and production method. By
the end of the second year following transplanting,
however, most of these differences disappeared. This
finding is consistent with Vanstone and Ronald
(1981) who found that the first-year effects of trans-
planting method on their species (including hack-
berry) did not persist into the second year.
The second year of this study was characterized by
the driest April through July on record in Ithaca, New
York. Whereas hackberry and hophornbeam put on
more shoot extension in year two than in year one in
spite of the drought, swamp white oak set less shoot
growth in year two. Yet of the three species, swamp
white oak had the heaviest leaf canopy and largest leaf
area both years and had negligible dieback in both
seasons. It appears that swamp white oak, while not
incurring dieback, responded to the drought by re-
ducing shoot extension though a full canopy of large
leaves was maintained. In the first year, hackberry had
the longest shoot extension of the three species, but
also had the most dieback. Rapid growth was noted in
the wet spring and early summer of 1998, growth that
was then checked by dieback in the drought of mid-
to late summer. In the second year, hackberry again
exhibited the most growth of the three species, but
this time had negligible dieback. Root growth that
took place in the intervening period between first-
and second-year measurements may have been suffi-
cient to support the rapid second-year shoot growth
without exhibiting any dieback. For all three species,
leaf area approximately doubled from year one to year
two in spite of the second-year drought.
Comparing Irrigation-Withheld Trees
For 40-mm-caliper (1.5-in.) swamp white oak
hydrogel-dipped if BR and normal handling if
306Buckstrup and Bassuk: Bare-Root vs. B&B Transplanting
B&B—there does not appear to be any advantage to
planting B&B in terms of ability to cope with
drought stress. The second year of this experiment
was the driest April through July on record; in that
year, there was no difference in growth response be-
tween B&B and BR trees. This finding challenges the
conventional thinking that under drought stress,
B&B trees are at an advantage over BR trees.
It is important to look at second-year growth in
this study. If looking at only first-year data, one could
assume that because B&B trees had significantly more
leaf canopy and leaf area than BR trees, B&B was su-
perior. However, year two showed a leveling out of
differences in the midst of record drought.
Research in Urban Settings
One concern about conducting research in urban
settings was the role of lurking variables. For ex-
ample, it was thought that soil texture might have a
confounding influence on measurements between
sites.
In Ithaca, where the great majority of soils in
this study were found to be gravelly loams, loams, or
silt loams, the concern was not with wet soils but
with excessive drainage and limited soil moisture
during two dry summers. The covariate analysis on
sand fraction addressed the concern that some sites
might be drier than others. The analysis revealed no
significant effects of this variable on the growth re-
sponses for any of the trees in either year. Soil pH
was also tested and was found sufficiently uniform to
prevent concern that it might confound results.
Other lurking variables include whether a home
owner watered trees or not, dog urination patterns,
children shaking tree trunks, and the like. This vari-
ability was not possible to control or quantify; how-
ever, the study employed a large number of
replicates to ensure that these variables would aver-
age out in the summary statistics.
It should be noted that the months of December
through March in the winter of 1997-1998 and De-
cember through February in the winter of 1998-1999
were warmer than normal. These comparatively
warmer winters may have benefited fall-planted trees
in this study by making winter injury less likely
CONCLUSION
Based on this study of B&B and hydrogel-dipped BR
trees harvested at 40-mm-caliper (1.5-in.) and
planted in the urban environment of Ithaca, New
York, recommendations on three street tree species
can be made. Hackberry can be successfully trans-
planted fall or spring, B&B or
BR.
BR
hackberry grows
better in fall than spring, and in spring, B&B trees
may grow better than BR trees, but all combinations
are viable. Hophornbeam can be successfully trans-
planted in the fall or spring, B&B or BR, although
spring
BR
planting may be risky, especially if trees are
not fully dormant when harvested. Swamp white oak
can be transplanted with success fall or spring, B&B
or BR. For all three species, differences in growth ob-
served in the first year can be expected to even out in
subsequent years. For swamp white oak, B&B does
not appear to offer an advantage over
BR
trees in times
of drought stress.
It is important to note several caveats. BR trees
were hydrogel dipped per the process described in the
materials and methods section. The dipping proce-
dure is a critical difference between the handling in
this study and common BR handling. Because we do
not assume that larger-caliper
BR
trees would perform
the same way as small-caliper trees, only trees under
50 mm (2 in.) caliper should be used to ensure sur-
vival and transplanting success. Trees must receive ad-
equate early maintenance in terms of mulching and
watering. Finally, results in other municipalities may
vary depending on weather patterns and soil types.
Soils on sites in this study were primarily gravelly
loams or silt loams; when dealing with clay soils, re-
searchers may see different results.
This study suggests that
BR
planting can be just as
viable as B&B transplanting for species that tolerate
being moved BR, are of relatively small caliper, are
root dipped, and are given proper early maintenance.
This has many time- and money-saving implications
for the field of urban forestry. BR trees are on average
one-third to one-half less expensive than B&B trees.
Because they are so much lighter and many more can
fit on the bed of a truck, they are cheaper to ship.
Planting BR trees costs virtually nothing when done
by volunteers with shovels. The cost of planting a
B&B tree, by contrast, is markedly higher because the
sheer weight of the ball requires machinery and ma-
chinery operators to load the tree, unload it, and to
get it into the ground. Because of the machinery used
to harvest them,
BR
trees have about 200% more roots
than B&B trees (Haug 1996). Furthermore, proper
Journal of Arboriculture 26(6): November 2000307
planting depth is enhanced by seeing the root flare on
BR trees, and soil interface problems are avoided. Fi-
nally, nursery field soil is not depleted by BR harvest-
ing. Given all these advantages and if, as in this study,
BR trees can be moved with just as much success as
B&B trees, BR deserves a second look from munici-
palities.
LITERATURE CITED
American Association of Nurserymen. 1996. American
Standard for Nursery Stock. American Association of
Nurserymen, Washington, DC.
Bailey Nurseries. 1999. Bailey Nurseries 1999-2000
Wholesale Catalog.
Berrang, E, and D. Karnosky. 1983. Street Trees for
Metropolitan New York. New York Botanical Garden
Institute of Urban Horticulture, Cary Arboretum,
Millbrook, NY. 291 pp.
Cool, R.A. 1976. Tree spade vs. BR planting. J. Arboric.
2:92-95.
Dirr, M.A. 1998. (5th ed.) Manual of Woody Landscape
Plants. Stipes Publishing Company, Champaign, IL.
1187 pp.
Gilman, E.E 1997. Trees for Urban and Suburban
Landscapes. Delmar Publishers, New York, NY. 662 pp.
Good, G.L., and T.E. Corell. 1982. Field trials indicate the
benefits and limits of fall planting. Am. Nurseryman
156(8):31-34.
Harris, J.R., and N.L. Bassuk. 1994. Seasonal effects on
transplantability of scarlet oak, green ash, Turkish
hazelnut and tree lilac. J. Arboric. 20:310-317.
Harris, J.R., E Knight, and J. Fanelli. 1996. Fall
transplanting improves establishment of balled and
burlapped fringe tree (Chionanthus virginicus L.).
HortScience 31:1143-1145.
Haug, M.C. 1996. Increasing transplant success of bare-
root street trees by minimizing water stress during
handling. M.S. thesis, Cornell University, Ithaca, NY.
Heisler, G.M., R.E. Schutzki, R.E Zisa, H.G. Halverson, and
B.A. Hamilton. 1982. Effect of planting procedures on
initial growth of Acer rubrum L. and Fraxinus
pennsylvanica
L. in a parking lot. Northeastern Forest
Experiment Station Research Paper NE 513. 7 pp.
Hensley, D.L. 1993. Harvest method has no influence on
growth of transplanted green ash. J. Arboric. 19(6):
379-382.
Hightshoe, G.L. 1988. Native Trees, Shrubs and Vines for
Urban and Rural America. Van Nostrand Reinhold,
New York, NY. 819 pp.
Hinesley, L.E. 1986. Effect of transplanting time on
growth and development of Fraser fir seedlings.
HortScience 21(l):65-66.
Kozlowski, T.T., and WJ. Davies. 1975. Control of water
balance in transplanted trees. J. Arboric. 1(1):1—10.
Magley, S.B., and D.K. Struve. 1983. Effects of three
transplant methods on survival, growth, and root
regeneration of caliper pin oaks. J. Environ. Hortic.
1:59-62.
Northern Nurseries, Inc. 1999. "Fall Hazards," Nursery
Catalog Insert.
Pirone,
P.E,
J.R. Hartman, M.A. Sail, and
T.P.
Pirone. 1988.
Tree Maintenance. Oxford University Press, New York,
NY.
Princeton Nurseries. 1999. Princeton Nurseries 1999-
2000 Wholesale Catalog.
Schein, R.D. 1993. Street Trees, A Manual for
Municipalities. Tree Works Publishers, State College,
PA. 398 pp.
Vanstone, D.E., and WG. Ronald. 1981. Comparison of
bareroot versus tree spade transplanting of boulevard
trees.
J. Arboric. 7(10):271-274.
Watson, G.W, and E.B. Himelick. 1997. Principles and
Practice of Planting Trees and Shrubs. International
Society of Arboriculture, Champaign, IL. 199 pp.
Watson, G.W, E.B. Himelick, and E.T. Smiley. 1986. Twig
growth of eight species of shade trees following
transplanting.]. Arboric. 12(10):241-245.
Witherspoon, W.R., and G.P. Lumis. 1986. Root
regeneration, starch content, and root promoting
activity in T. cordata cultivars at three different
digging-planting times. J. Environ. Hortic. 4:76-79.
Acknowledgments. The authors wish to sincerely
thank the International Society of Arboriculture Research
Trust for funding this research. We also appreciate the in-
valuable and conscientious participation of Ithaca city for-
ester Andrew Hillman and tree crew members Rose
Marrabitt and Eric Woodward. Sincere thanks go to Jim
Kisker and George Schichtel of Schichtel's nursery for their
collaboration on this project. We thank Donald Rakow, Me-
lissa Luckow, and George Good for carefully editing the
manuscript and recognize Dr. Rakow and Dr. Luckow for
serving on the graduate committee for this study
^Former Graduate Student
Urban
Horticulture
Institute
Cornell
University
Ithaca, NY
(Home
address)
P.O.
Box241
Trumansburg,
NY 14886
emailmb90@cornell.edu (continued)
308Buckstrup and Bassuk: Bare-Root vs. B&B Transplanting
2Director
Urban Horticulture Institute
20 Plant
Science Building
Cornell University
Ithaca NY 14853
email
nlb2@cornell.edu
*
Corresponding
author
Resume. Dans cette etude, des micocouliers
(.Celtis
occidentalis),
des ostryers de Virginie (Ostrya
virginiana)
et
des chenes bicolores
(Quercus bicolor)
de 40 mm produits
en panier de broche et a racines nues ont ete regroupes
ensembles et plantes sur des sites autour de la ville de
Ithaca dans l'etat de New
York.
La moitie des arbres ont ete
plantes en automne et l'autre moitie au printemps. Les
racines des arbres a racines nues ont ete enduites d'un hy-
drogel en pepiniere afin de prevenir la dessication de ces
dernieres apres l'arrachage. Les taux de survie ont ete
excellents pour toutes les combinaisons de traitement a
l'exception des ostryers a racines nues plantes au printemps
qui ont eu un taux de mortalite de 50%. Des mesures de
croissance ont ete prises en aout de la premiere et de la
seconde saison de croissance. Les resultats de la premiere
annee ont montre plusieurs differences significatives entre
les divers groupes. A la fin de la seconde saison cependant,
peu de differences significatives persistaient entre les divers
groupes. Durant la premiere saison de croissance, les
micocouliers a racines nues plantes en automne ont mieux
pousse que ceux en paniers de broche. La croissance des
micocouliers en panier de broche plantes au printemps etait
meilleure. Les ostryers plantes en automne, a racines nues
ou en panier de broche, ont bien repondu. Le chene
bicolore poussait quelque peu mieux en panier de broche
qu'a racines nues peu importe la saison de plantation. Les
chenes bicolores plantes a racines nues ou en panier de
broche en automne poussaient quelque peu mieux que
leurs congeneres plantes au printemps. Une etude separee
sur le chene bicolore
s'est
attardee sur l'impact de la dimi-
nution de l'irrigation sur les sujets plantes au printemps, a
racines nues et en panier de broche. Les chenes a racines
nues et ceux en panier de broche ont pousse de maniere
equivalente apres deux saisons de croissance caracterisees
par une secheresse.
Zusammenfassung. In dieser Studie wurden ballierte
und als Wurzelware gerodete Celtis
occidentalis,
Ostrya
virginiana
und
Quercus bicolor
paarweise auf Standorte in
der Stadt Ithaka, N.Y., gepflanzt. Die eine Halfte wurde im
Herbst, in anderen im Fruhling gepflanzt. Die Wurzelware
erhielt ein Hydrogel Wurzeldip, um ein Wurzelsterben
nach dem Roden zu minimieren. Die Uberlebensraten
waren ausgezeichnet bis auf die im Fruhling als Wurzelware
gepflanzten Ostrya, die zu 50 % ausfielen. Im August der
ersten und zweiten Wachstumsperiode wurden Wachs-
tumsmessungen vorgenommen. Gegen Ende der zweiten
Wachstumsphase zeigten sich nur wenige deutliche
Unterschiede zwischen den Behandlungen. Wahrend der
ersten Wachstumsphase wuchs die im Herbst gesetzte
Celtis
als Wurzelware besser als die ballierte. Das Wachstum der
im Fruhling gepflanzten Celtis war besser bei den ballierten
Baumen. Im Herbst gesetzte
Ostrya,
balliert und als Wurzel-
ware reagierte ahnlich, aber die im Fruhling gesetzten
ballierten Pflanzen wuchsen besser.
Quercus
mit Ballen
wuchs etwas besser als ohne, unabhangig von der Jahres-
zeit. Beide
Quercus
wuchen im Herbst besser als die im
Fruhling gepflanzten. Eine separate Studie an der
Quercus
bicolor
beschaftigte sich mit dem Einflufi von ausgesetzter
Wasserung auf im Fruhling gepflanzter Baume, balliert und
ohne Ballen. Beide reagierten gleich gut nach zwei
Wachstumsperioden, die durch Trockenheit gekennzeich-
net waren.
Resumen. En este estudio fueron plantados parejas de
arboles, de 40 mm (1.5 in) de diametro a ralz desnuda (RD)
y con bola en arpillera (B&B), de Celtis occidentalis, Ostrya
virginiana y Quercus bicolor, en sitios alrededor de la
ciudad de Ithaca, New York, USA. La mitad de los arboles
fueron plantados en otono y la otra en primavera. Los RD
recibieron en el vivero un hidrogel en las raices para prev-
enir la desecacion posterior a la cosecha. Las tasas de super-
vivencia fueron excelentes para todas las combinaciones de
tratamientos excepto para los O. Virginiana plantados en
primavera, los cuales experimentaron un 50% de mortal-
idad. Se tomaron mediciones de crecimiento en Agosto en
la primera y segunda estacion de crecimiento. Los result-
ados del primer ano mostraron muchas diferencias sig-
nificativas entre los tratamientos. Para el final de la segunda
estacion de crecimiento, sin embargo, persistieron muy
pocas diferencias. Durante la primera estacion de crecim-
iento,
los C. occidentalis plantados en otono a RD crecieron
mejor que los B&B. El crecimiento en primavera fue mejor
en los arboles de C. Occidentalis plantados en
B&B.
Los O.
Virginiana plantados en otono respondieron bien tanto a
RD como en B&B. Q. Bicolor creci6 algo mejor en B&B
que a RD, sin importar la estacion. Ambos Q. Bicolor a RD
y en B&B plantados en otono crecieron algo mejor que sus
contrapartes de primavera. Un estudio separado con Q. Bi-
color reviso el efecto del riego en primavera tanto a RD
como con B&B. Los dos se comportaron igualmente bien
despues de las dos estaciones de crecimiento caracterizadas
por sequia.
... Field-grown BR production of trees requires removal of the soil from the root system, and can be economically advantageous to the grower due to the elimination of container costs, retention of field soil, and decreased water use (Reiger and Whitcomb, 1982;Harris and Gilman, 1993;Richardson-Calfee and Harris, 2005). Bare-root trees may require further preventative measures such as root-dipping in hydrogel (a hydrophilic absorbent polymer substance) to prevent root desiccation following harvest (Buckstrup and Bassuk, 2000;Landis and Haase, 2012). Bare-root and B&B plants are often larger at the time of transplanting than containerized nursery stock, but may sustain greater mortality rates compared to smaller trees due to a number of production-based practices (Struve, 2009). ...
... had a higher percentage of survival than BR trees (of which 80-90% of trees survived) ten years after planting, though this slight advantage was not statistically significant. Buckstrup and Bassuk (2000) compared growth responses of B&B and BR trees, transplanted in the spring and the fall into urban "tree lawns" ranging from 5 to 15 feet in width. The trees examined in this experiment were Celtis occidentalis L., Ostrya virginiana (Mill.) ...
... However, B&B C. occidentalis out-performed BR trees when transplanted in the spring. All species and treatments fared well with few significant differences after the first year (Buckstrup and Bassuk, 2000). This study confirmed the viability of using BR production as an alternative to B&B during the fall transplanting season for these common urban tree species. ...
Article
Urban trees face a myriad of complex challenges growing in the built environment. The most common environmental conditions influencing urban tree mortality are water availability, nutrient deficiency and soil compaction. Long-term survival of recently installed trees has been directly attributed to site conditions, planting technique, and post-transplant maintenance. Tree survival is also dependent on selection of healthy, suitable plant material. Production methods for woody plants include traditional plastic containers (CG), pot-in-pot containers (PIP), and in-ground fabric containers (IGF). Field grown trees may be produced as bare-root (BR) or root ball-excavated and burlap-wrapped (B&B) trees. Each of these methods offers unique advantages in relation to production and installation. Many of the studies reviewed reveal varying post-transplant establishment and survival responses to production methods at a species-specific level.
... Initial canopy volume for each plant was calculated as the product of the height and width in two directions (in row and perpendicular). Initial canopy volumes (SE in parentheses) were 0.11 (0.007) m 3 (6) with 100% pinebark (actual = 0.1748 + 0.5269 (measured), r 2 = 0.85). The Theta Probe uses time domain reflectometry (1) to mea-sure the average volumetric water content from the top to the bottom of the 6 cm (2.5 in) long metal probes and the substrate surrounding the probes. ...
... Reports on the effect of transplant season on post-transplant growth of other species have mixed results. Fall planting is reported to increase post-transplant growth compared to spring transplanting by some (3,22), to decrease growth compared to spring transplanting by others (7,20), or to have no affect on post-transplant growth (11,21). These conflicting results are probably due to genotype X environment interactions, such as was evident between our study and that by Wright et al. discussed above. ...
Article
Mountain laurel (Kalmia latifolia L.) is a common native shrub in the Eastern United States; however, this species can be difficult to establish in landscapes. Two experiments were conducted to test the effects of transplant season and container size on landscape establishment of Kalmia latifolia L. ‘Olympic Wedding’. In experiment one, 7.6 liter (2 gal) and 19 liter (5 gal) container-grown plants were planted into a simulated landscape (Blacksburg, VA, USDA plant hardiness zone 6A) in early fall 2000 and in late spring 2001. Plants in 19 liter (5 gal) containers had the lowest leaf xylem potential (more stressed) near the end of the first post-transplant growing season, and leaf dry weight and area were higher for spring transplants than for fall transplants. For spring transplants, 7.6 liter (2 gal) plants had the highest visual ratings, but 19 liter (5 gal) plants had the highest visual ratings for fall transplants three growing seasons after transplanting. Plants grown in 7.6 liter (2 gal) containers had the highest % canopy volume increase after three post-transplant growing seasons. In the second experiment, 19 liter (5 gal) plants were transplanted into above-ground root observation chambers (rhizotrons) in early fall 2000 and late spring 2001. Roots of fall transplants grew further into the backfill than spring transplants at the end of one post-transplant growing season. Overall, our data suggest that smaller plants will be less stressed the first season after transplanting and will likely stand a better chance for successful establishment in a hot and dry environment. Fall is the preferred time to transplant since capacity for maximum root extension into the backfill will be greater than for spring transplants.
... bicolor has been reported to be an easy-transplant tree (e.g. Bassuk 1990, Buckstrup and Bassuk 2000, Curtis 2000, while Q. rubra is considered a relatively difficult to transplant (e.g. Struve et al. 2000, Struve 2009). ...
... Overall, Q. bicolor trees survived transplanting better than Q. rubra (Table 1). This result is consistent with the observations in the previous studies (Buckstrup andBassuk 2000, Struve 2009). One IGF Q. bicolor tree died four months after transplanting, while all of the other Q. bicolor trees survived. ...
Article
Full-text available
The objective of this study was to investigate the post-transplant, root specific hydraulic conductance (KS) of two oak species (Quercus bicolor Willd. and Quercus rubra L.). Q. bicolor and Q. rubra trees responded differently to transplanting across the differing types of production methods. Overall, higher post-transplant fine root KS resulted in a larger leaf area after transplanting. Container-grown (CG) trees had the highest root KS immediately after transplanting compared to balled-and-burlapped (BNB), in-ground fabric (IGF), and bare-root (BR) trees, but KS in CG trees was largely reduced at the end of the first growing season after transplanting. Post-transplant variations of fine root KS also differed between the two tree species. Fine root KS remained similar in BNB and IGF Q. bicolor trees after transplanting, but increased with time after transplanting in Q. rubra trees. The increase in KS was especially greater in BNB and BR Q. rubra trees than IGF Q. rubra. Index words: transplanting, root hydraulic conductance, tree production method, Quercus bicolor, Quercus rubra, oak. Species used in this study: Swamp white oak (Quercus bicolor Willd.); northern red oak (Quercus rubra L.).
... Numerous studies compared post-transplant response of FG trees moved as B&B to those moved BR. Findings of some studies have shown higher mortality in BR trees compared to B&B trees, especially in regions that experience severe heat and drought (Buckstrup 2004;Sather et al. 2004;Etemadi et al. 2013), while other studies have suggested that if BR trees transplanted with proper care (roots dipped in a hydrophilic gel immediately after harvesting and wrapped in a plastic bag to keep the roots moisture), no significant difference could be observed between two methods (Buckstrup and Bassuk 2000;Anella et al. 2008;Jack-Scott 2012). ...
... By the end of the second year of the current study, the significant differences observed between B&B and CG trees disappeared for all measured variables. It was also found in some previous studies that first year effects of transplanting method may not persist in the following years (Vanstone and Ronald 1981;Buckstrup and Bassuk 2000;Etemadi et al. 2013). This observation is of significant importance, as it shows freshly dug oriental thuja trees can be successfully transplanted using the prevalent B&B method without the hardening-off process, which requires more time, labor, and expense. ...
... When planting trees in restoration projects, the most common practice is to use containerized (CT) trees, which are often one of the largest costs to property owners, lake managers, and restoration practitioners. As an alternative to CT trees, dormant bare-root (BR) trees can be used at half the cost due to reduced weight and associated ease of handling, which facilitates more cost-effective shipping from nurseries to restoration sites (Buckstrup & Bassuk 2000). ...
... BR trees in the nursery and landscape industry have been used for decades and are commonly used in surface mine reclamation projects (Salifu et al. 2009;Wilson-Kokes et al. 2013), reforestation (Gardiner et al. 2005;Holmes & Webster 2014), stream and lake riparian restoration (Sweeney et al. 2002;Haskell 2009), and urban landscaping (Cool 1975;Vanstone & Ronald 1981;Buckstrup & Bassuk 2000). Many studies have compared BR stock to CT stock with mixed results (Grossnickle & El-Kassaby 2015). ...
... Further improvements are needed to achieve standardization in the chemical quality of the soil and to ensure the reliability of the decontamination treatment, and more investigations are needed to assess its suitability for specific types of nursery production. For example, the coarse and loose structure of the remediated sediments could be advantageous in productions that require easy soil removal from the root ball, like plants that need transplanting within the nursery production cycle (Mason, 2004;Jack-Scott, 2012), or for the sale of bare-rooted plants (Hensley, 1993;Bassuk, 2000;Buckstrup and Bassuk, 2000;Yang and McBride, 2003). More attention should be given to determining the extent to which sediments show the best performance, either by enhancing their structural homogeneity e by applying a mechanical treatment e or by mixing different percentages or different alluvial soils. ...
Article
When canals and harbours are dredged, huge amount of polluted sediments has to be stocked and transported to the landfill with incredibly high costs of management. Among the remediation techniques for the reclamation of polluted sediments and soils, phytoremediation represents a sustainable and effective technique though still not fully promoted or commercialized. In this study we have tested the suitability for plant nursing of a substrate resulting from sediments dredged from a canal and treated with phytoremediation. The experiment was set up in 2014. It aimed to test the physical, chemical and hydrological characteristics of two mixes of remediated sediments and agronomic soil (at 33% and 50% by volume) compared to control soil (100% agronomic soil), and to assess the growth of three ornamental species (Viburnum tinus L., Photinia x fraseri var. red robin, Eleagnus macrophylla Thunb.) together with the suitability for root balling. The mixed substrates produced good results in terms of water drainage, and were similar to the control in terms of soluble nutrients, guaranteeing and enhancing the aboveground and belowground growth of all the three species, especially V. tinus. In contrast, mixed substrates impaired root ball compaction with root ball breakage observed especially in 50% sediment/soil mix. Therefore, the use of remediated sediments in plant nursery can be limited to specific productions or practices.
... Each method offers advantages and disadvantages with regard to cost, handling, planting, and early care that must be considered when selecting and planting trees. While research has shown that some methods of nursery production can outperform others in the landscape (Gilman, 2001), transplant success is generally similar for the different methods of production when proper care is given (Buckstrup and Bassuk, 2000;Anella et al., 2008;Koeser et al., 2014). ...
Chapter
While urban forest regeneration does occur naturally, many of the trees found in urban areas were intentionally planted. Conventional transplanting processes can be quite stressful for a tree. Field grown trees can lose a significant portion of their roots during harvest. All trees, regardless of how they were produced, can experience drought stress, mechanical damage, and exposure to extreme temperatures as they are transported, staged, and planted. These stresses and their impact on the success or failure of urban plantings have received considerable attention among researchers in arboriculture, urban forestry, and tree physiology. Their work has helped identified best practices for tree handling and installation which can reduce negative impacts to a tree’s long-term growth and survival. This chapter details some key considerations to promote successful tree planting. It includes information on minimum planting space requirements, seasonal impacts, proper tree storage and handling, planting hole excavation and backfilling, and early care practices (e.g. staking, mulching, pruning, etc.). Trees are typically sold as balled-and-burlapped, container, or bare-root nursery stock. Variations in handling and planting practices related to these production and delivery methods are noted where appropriate. This chapter also highlights planting practices that are specific to planting woody palms.
Article
Container-grown shade trees make up an increasing proportion of nursery stock, yet arborists and urban foresters are often concerned about root defects associated with trees grown in smooth-sided containers, such as circling roots, persisting in the landscape post-transplant. The objective of this study was to determine the effect of root modifications (shaving or bare-rooting) at planting on establishment, survival, and growth of container-grown Acer rubrum L. ‘October Glory’, Liriodendron tulipifera L. ‘Fastigiatum’, and Platanus x acerifolia (Aiton) Willd. ‘Bloodgood’. Trees were planted on two dates (May and July) in 2018 and evaluated for two growing seasons. Modifying roots before planting resulted in increased occurrence of leaf scorch for L. tulipifera and A. rubrum trees. Nearly all trees bare-rooted before planting in July had severe die-back. Survival was excellent (>75%) for all A. rubrum and P. x acerifolia trees planted in May regardless of treatment. Survival for L. tulipifera trees that were bare-rooted in May was 50%; all L. tulipifera trees that were bare-rooted in July died. Bare-rooting increased predawn leaf water potential (Ψw) immediately after planting. However, Ψw did not differ among root treatments for the rest of 2018 and throughout 2019. This suggests that trees with modified root systems achieved a functional equilibrium by adjusting leaf area to reduce whole-tree water loss. Root biomass outside the original root-ball did not differ among root modification treatments two years post-transplant. However, bare-rooting reduced the proportion of circling roots compared to control trees for all species. Shaving root systems reduced circling roots compared to the control for L. tulipifera and P. x acerifolia trees. For practitioners interested in trialing these techniques, we advise performing root modifications in the dormant season and avoiding species known to be difficult to transplant bareroot.
Chapter
The increasing proportion of paved surface due to urbanization means that the conditions for urban trees and vegetation to survive have deteriorated. Factors such as air pollution, poor drainage, and the lack of usable soil for root growth contribute to the short life expectancy of urban trees. To meet this challenge, several permeable and “structural” or “skeletal soils” have been developed as alternatives to the typical compacted soil required to bear the weight of vehicular traffic in urban areas. The main objective of this study is to evaluate the resistance to permanent deformation of permeable and skeletal soil pavement structures based on full scale accelerated pavement tests (APT) using a heavy vehicle simulator (HVS). Interlocking paving stones of various types were used as permeable surface layer for the test structures. The results demonstrated that the permeable test structures exhibited higher permanent deformation than the corresponding impervious structures. The skeletal soil with bituminous base layer, however, produced performance comparable to the impervious reference test structures.
Article
Slow growth following transplanting is characteristic of the establishment period, which has been studied for many years. Most of this work, however, has been conducted on trees transplanted in nurseries or favorable growing sites. In urban areas, many trees are transplanted into more challenging growing conditions, and very few studies have investigated establishment period of such trees. We analyzed ten years of transplanting records for the metropolitan Boston, MA, USA area to determine the establishment period of three species commonly planted as street trees {hedge maple [Acer campestre L.], London planetree [Platanus x acerifolia (Ait.) Willd.], and red oak [Quercus rubra L.]}. Using piecewise linear regression, we determined the “break point,” the intersection of two lines fitted to a scatter plot of caliper versus years after transplanting. The break point indicates the number of years after transplanting at which growth rate increases—the establishment period. We also analyzed whether site factors affected stem caliper. Establishment period varied among species: 2.1 years, 4.0 years, and 5.9 years for red oak, London planetree, and hedge maple, respectively. Site factors variably affected stem caliper of different species. Stem caliper of London planetree and red oak increased with greater sidewalk cut-out area. Tree grates in sidewalk cut-outs adversely affected stem caliper of London planetree. Our results can help practitioners manage street trees in the northeastern United States, but more work on trees transplanted in urban areas is necessary to understand the initial post-transplant growth of street trees.