United States 

Depart men t of 

Agriculture 

Forest Service 

Northeas tern Forest 

Experiment Station 

Research 

Paper N E-513 

Effect of Planting Procedures 

on Initial Grow 

of Acer rubru 

Fraxinus pe 

in a Parking 

Gordon M. Heisler 

Robert E. Schutzki 

Robert P. Zisa 

Howard G. Halverson 

Bruce A. Hamilton 
The Authors 

Gordon M. Heisler is a research forest meteorologist with the forest 

amenities and municipal watersheds project, Northeastern Forest Experiment Station, University Park, PA. He has a B.S. degree from The Pennsylvania State University, a Master of Forestry from Yale University, and a 

Ph.D. in forest influences from the State University of New York, College of 

Environmental Sciences and Forestry. He joined the Forest Service in a research capacity in 1972. 

Robert E. Schutzki was a research assistant in ornamental horticulture 

at Rutgers University during the course of this study. He has a B.S. in landscape architecture and an M.S. in ornamental horticulture from Rutger's 

University. He is currently Coordinator for the Agricultural Technology twoyear program in Landscape and Nursery at Michigan State University, East 

Lansing. 

Robert P. Zisa is now a forester with the Bureau of Indian Affairs, 

Hoquiam, WA. During the course of this study he was with the urban forestry unit of the Northeastern Forest Experiment Station at University Park, 

Pennsylvania. He received his B.S. and M.S. degrees through the Department of Horticulture and Forestry, Cook College, Rutger's University. He 

joined the Forest Service in 1974. 

Howard G. Halverson is research forester and Project Leader for forest 

amenities and municipal watershed research at the Northeastern Forest Experiment Station, University Park, PA. He received his B.S. degree in forest 

management from Iowa State University and M.S. and Ph.D. degrees from 

the University of Arizona. He began his career with the Forest Service in 

1965 and came to the Northeastern Station in 1975. 

Bruce A. Hamilton is associate professor of ornamental horticulture in 

the Department of Horticulture and Forestry, Cook College of Rutgers University. He received his B.S. in horticulture from Rutgers, and an M.S. in 

horticulture and Ph.D. in genetics from the Pennsylvania State University. 

Manuscript received for 

publication 11 November 1981 

Abstract 

Five-year old red maples, Acer rubrum b. 'October Glory', and green 

ash, Fraxinus pennsylvanicum b. Marshall Seedless', were planted in 8 ft x 

8 ft openings in an asphalt parking Iot with two planting stocks (bare-root, 

BR, and balled and burlapped, B&B) and two fertilizer levels (a control and 

1.36 kg of 10-30-10 fertilizer along with 1.36 kg of dolomitic limestone per 

tree). After two growing seasons, survival of the 32 trees was 100 percent, 

and they grew better thha trees similarly planted off the lot. Fertilizer reduced growth of BR green ash; increased shoot growth, but not height or 

crown width growth of BR red maples; and had a negligible effect on 

growth of B&B trees of either species. BR red maples and unfertilized BR 

green ash generally grew better than corresponding B&B trees. 
Introduction 

Urban development has altered 

our physical environment by replacing native soil and natural vegetation with large areas of impervious 

surfaces such as parking lots. This 

development leads to extremes of 

heat and radiation which create an 

undesirable urban climate. Solar radiation impinges directly on pedestrians and is absorbed by asphalt 

surfaces. The surfaces are heated 

and act as sources of longwave radiation and of sensible heat to the 

air above them. Trees can ameliorate undesirable parking lot environments by shading people, vehicles, 

and parking lot surfaces. 

Trees may be established in 

many parking lots with very little 

loss of space for parking cars (Nelson and Porter 1976). To achieve environmental benefits in a reasonable 

time, it is necessary to plant them 

by methods that promote rapid 

adaptation, growth, and development. However, there is little information about planting methods, nutrient needs, and desirable species 

for urban environments (Cool 1980). 

Many ordinances and landscape specifications require that 

large trees be planted with roots 

balled and burlapped (B&B) rather 

than bare-root (BR), because it is 

presumed that B&B trees have 

greater survival and initial growth 

rates. However, there is little evidence from formal studies in the 

literature to support this supposition. B&B trees are more expensive 

to lift, transport and plant than BR 

trees. The BR method of planting 

may be more attractive if survival 

and growth rates are comparable to 

those of the balled and burlapped 

stock. 

Fertilization at planting time is 

another practice with insufficient research data to support a standard 

recommendation. Some contend 

that because of root damage during 

transplanting, trees may be unable 

to use added nutrients; and further, 

newly developing roots may be injured by a fertilization treatment. 

Others maintain that the soil backfill 

must be enriched with fertilizer because that is likely to be the only 

fertilizer the plant will ever receive. 

A study was therefore initiated 

to improve guidelines for introducing trees into the urban setting, 

with particular emphasis on the urban parking lot, The primary study 

objective was to evaluate the effect 

of two planting methods (stocks) 

and a fertilizer treatment on early 

survival and growth of two deciduous species. A secondary objective 

was to provide a demonstration of 

the functional and aesthetic benefits of trees in a parking lot. This paper presents the results of growth 

measurements after the first and 

second growing seasons. 

Methods 

Thirty-two trees of two deciduous species (16 trees of each) were 

planted in openings cut in a large 

parking lot. The two species were 

red maple (Acer rubrum L.) cultivar 

'October Glory' and Marshall Seedless' green ash (Fraxinus pennsylvanicum 1.). These two species have 

proven to be relatively tolerant of urban stresses (Mew Jersey Federation of Shade Tree Commissions 

1974). The trees were 5 years old 

and averaged about 2.5 rn tall. Half 

of the trees of each species were 

balled and burlapped and half were 

bare root. Half of the trees received 

a fertilizer treatment at the time of 

planting. 

The parkifig lot, located on the 

Cook College Campus at Rutgers 

University in New Brunswick, NJ, is 

about 190 m long and 50 m wide. 

The surface slopes slightly toward 

storm-sewer drains along one side. 

Before construction of the lot, the 

land was used for field crops, and 

during the course of this experiment, the surrounding land on three 

sides remained in field crops and 

experimental turf plots. 

The parking lot was constructed on poorly-drained Nixon silty 

clay loam soil. During construction 

of the lot in 1972, a layer of soil was 

removed. Much of this soil, including the topsoil, was stored in a tow 

pile along the edge of the lot. After 

removal of the soil layer, a 30-cm 

sand base was laid down and covered with asphalt. The present slope 

approximates the slope of the land 

before construction. 

The experimental design was a 

factorial combination of eight treatments (2 species x 2 planting methods x 2 fertilizer levels) with four 

replications representing four 

blocks. The blocks were used to 

separate possible gradients in soil 

fertility and moisture availability 

along the length of the parking lot. 
In order to accommodate our 

trees, 32 planting sites were cut in 

the asphalt between parking stalls 

using a "diamond" pattern. This arrangement, suggested by Nelson 

and Porter (1976), allowed inclusion 

of the trees in the lot with no loss 

of parking spaces. Each site was 

2.6 m by 2.6 m (Fig. 1). 

The planting sites were distributed across the lot at a density of 

about one tree per 10 stalls. The 

spacing was based on requirements 

of typical municipal landscape ordinances (Cherry Hill, New Jersey, Ordinance 69-24 and Hillsborough, 

New Jersey, Ordinance 75-1 3). 

After removal of the asphalt 

with jack hammer and backhoe, the 

planting sites were prepared by excavating the sand and soil to a 

depth of approximatery 45 cm below 

the top of the asphalt. Then, four 

railroad ties were permanently anchored around each planting hole to 

act as curbing. The holes were then 

refilled with the silty clay loam soil 

from the pile created during construction of the lot. The surface of 

the added soil was 10 to 15 cm 

above the top of the asphalt. Physical and chemical characteristics of 

the backfill, soil stored during lot 

construction, are listed in Table 1. 

Table 1 .-Physical and chemical 

characteristics 

sf the backfill soil. 

pH (water) 

Organic matter 

(L.I., % dry 

weight) 

Texture analysis: 

Silt percent 

Clay percent 

Sand percent 

Classification 

Exchange capacity 

(meq1100 g) 

(extraction 

with NHdOAc, 

pH = 7) 

Available nutrients 

(ppm): 

Nitrogen 

(assumed as 

2% of total N) 

Phosphoras 

Potassium 

Magnesium 

59 

35 

6 

silty clay loam 

The trees were acquired from a 

local nursery and planted in late 

April. They were 3.0 to 4.0 cm in 

caliber at 30 cm above the soil line, 

and between 2.0 and 3.6 m in 

height. The B&B trees had soil balls 

approximately 40 cm in diameter 

and 45 cm in depth. Reasonable 

care was taken to minimize root 

desiccation of the bare-root stock 

during the time between receipt and 

planting. 

The fertilization and lime treatment consisted of an application of 

a complete inorganic fertilizer 

(10-10-10) and pulverized dolomitic 

limestone (min. CaC03 51.5%, min. 

MgC03 44.0%). The soil amendments were based on a nutritional 

study of seedling red maples conducted before the beginning of this 

project by Pham et al. (1978). They 

related the existing nutrient status 

of the planting soil (Table 1) to acquire results based on growth responses, and calculated the treatment rate at 1.36 kg of the N-P-K 

fertilizer and 1.36 kg of the pulverized limestone. The soil amendments were hand mixed in the appropriate planting sites with approximately 0.3 m3 of planting soil, immediately before tree planting at 

Figure 1.-Diamond planter pattern used within the diagonal parking stalls. 
each of the treated sites. After 

planting, the fill gradually settled 

and a thin layer of wood chips was 

added to control weeds and conserve soil moisture. 

At the time of planting, trees 

were pruned according to guidelines 

established by the New Jersey Federation of Shade Tree Commissions 

(1974). Approximately two-thirds of 

the crown was removed from the 

bare rooted trees of each species. 

Pruning on the balled and burlapped 

trees of both species consisted of 

the removal of broken, dead, or conflicting branches from the crown. 

Soil temperature and moisture 

were not considered as variables in 

this study. However, thermocouple 

psychrometers were installed at 

each planting site in September of 

the first growing season, and observations of temperature and moisture 

were made weekly through the second growing season. 

Soil moisture was quite high 

during the second growing season. 

During the weekly observations, 

only one planter box was found to 

have soil moisture below -1 bar tension. Soil psychrometers are limited 

to measuring soil tensions of about 

-I bar or less. The soil tensiometers 

indicated soil moisture between 3 

and 37 centibars tension, but there 

were differences among the five 

planting sites. The ranges of observed moisture tension were 3 to 6, 

4 to 7, 4 to 9, 5 to 18, and 8 to 37 

negative centibars for the five sites. 

Additional informat ion about 

moisture conditions was obtained 

from 1.2-rn-deep ground water wells 

at four widely-spaced planting sites 

across the lot. During most of the 

summer, measurements showed a 

relatively high water table, probably 

due to rain water flowing across the 

lot surface and seeping beneath the 

ties into the relatively large planting 

openings, generally poor horizontal 

drainage of the site, and the lack of 

upward movement of water through 

the impervious asphalt, which limited evaporation. Our observations 

did not show any general soil-moisture gradient across the lot. 

The second season had 48.8 cm 

of rain, (April through August), 

which is close to the long-term 

norm. We believe that moisture was 

not severely limiting during the first 

growing season, although rainfall 

was only 37.3 cm, about 24 percent 

below normal. 

No severe soil temperatures 

were noted in the weekly measurements between November following 

the first growing season and the 

January following the second season. Maximum soil temperatures exceeded control temperatures by 

3" C beneath the parking lot trees 

and up to 10" C beneath the asphalt 

cover (Halverson and Heisler 1981). 

Treatment effects were determined by a variety of different measurements of tree growth after the 

first and second growing seasons: 

total tree height, crown width, 

crown height, diameter at 30 cm 

above the soil, average shoot 

growth, and average leaf area and 

dry weight. Crown width and crown 

height were averaged to form a 

composite "average crown dimension" (ACD). 

Crown width was measured in 

both the north-south and east-west 

directions. Measurements were taken horizontally through the widest 

point of the crown in each direction. 

Shoot elongation was measured 

on six shoots on each tree. Three 

shoots of similar diameter were chosen from the north and south sides 

of each tree at midcrown height. 

Leaf area and dry weight were 

recorded as the average of 30 leaves 

from each tree. The leaves were collected in mid-August from the midcrown and upper crown of the north 

and south side of the trees. Petioles 

were separated from the blade, and 

blade area was recorded with a leaf 

area meter1 immediately after collection. Leaf blades were then ovendried at 70°C and their dry weight 

was recorded. 

Observations of leaf area, dry 

weight, shoot growth, and height 

growth are available for both growing seasons. Data for diameter 

growth and crown width growth are 

available for the second growing 

season only. 

Analysis of variance was used 

to test for significant treatment effects. Duncan's multiple range test 

(Steel and Torrie 1960) with a = 0.05 

was used for mean separation. 

Eight planters similar to those 

on the lot were constructed about 3 

m off the lot in a row parallel to the 

southern end of the lot. Random 

species and stock treatments were 

applied to trees planted there so 

that there were four green ash and 

four red maples with two trees of 

each stock in each species; but no 

fertilizer was applied. Soil moisture 

and temperature were measured 

during the second growing season 

in the same manner as for on-lot 

sites. The eight trees off the lot provide something of a control against 

which to compare growth of on-lot 

trees. 

An important difference between on-lot and off-lot planters 

was that off the lot the original surface soil was not disturbed except 

for a hole in the center large 

enough to plant the tree. Hence, below the 15 cm of soil added to bring 

the soil level up near the top of the 

ties, the soil was quite dense, except for the looser soil in the planting hole. This is in contrast with the 

soil on the lot, which had been 

hauled in and was relatively loose. 

Results 

All of the trees survived the 

first two growing seasons. After 

rather slow growth during the first 

season as they were becoming established, the trees generally put on 

good growth during the second 

growing season. 

Portable area meter, model LI-3000, 

manufactured by Lamda Instruments 

Corporation, Lincoln, Nebraska. 

The use of trade, firm or corporation 

names in this publication is for the 

information and convenience of the 

reader. Such use does not constitute an 

official endorsement or approval by the 

U.S. Department of Agriculture of any 

product or service to the exclusion of 

others that may be suitable. 
Analysis of variance of the Many comparisons of treatment 

growth responses showed signifi- show no statistically significant difcant interactions between the main ferences. The measurements of diaeffects of species, stock, fertilizer, meter growth, which were made for 

and year. Mean separation for each the second year, showed no signifigrowth response was done by four cant differences due to treatments 

separate analyses of the four treat- for either species. 

rnents within each species and year 

group. This analysis provides com- Response to Fertilizer parisons of stock and fertilizer treatment effects within species for B&B trees did not respond to 

each year (Table 2). the fertilizer treatment during the 

first growing season. In the second 

year, B&B red maple responded to 

fertilizer by increased leaf area and 

leaf dry weight, but B&B green ash 

still showed no statistically significant response to fertilizer. 

The BR trees did respond to 

fertilizer during the first growing 

season; but the response was in different directions. Red maple 

showed a positive response by inTable 2.--Summary of treatment means and mean separation analysis. Within each group of four 

mems for a given year and species combination, means with the same letter superscript 

are not significantly different. 

Leaf Leaf dry Shoot Height Diameter Crown width ACD 

Year Treatment area weight growth growth growth growth growth 

First 

Wed maple 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 

Green ash 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 

Second 

Red maple 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 

Green ash 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 

Sum 

Red maple 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 

Green ash 

B&B, Control 

B&B, Fertilized 

BR, Control 

BR, Fertilized 
creased shoot growth, although leaf 

area, leaf dry weight, and height 

growth were unchanged. In contrast, response of BR green ash to 

fertilizer was negative, with a large 

reduction in all four measures of 

growth that were observed. In the 

second year, BR red maple trees 

had no significant response to fertilizer. Response of fertilized BR green 

ash trees was again generally negative, with significantly less leaf area, 

shoot growth, crown width growth, 

and average crown dimension 

growth. 

Comparison of B&B Versus BR 

During the first growing season, growth of BR red maples exceeded that of B&B trees in leaf 

area, dry weight, and height growth. 

Shoot growth of fertilized BR trees 

was much greater than shoot 

growth of red maples in any other 

treatment (Table 2). 

First year response among the 

green ash treatments was mixed. 

Control BR trees grew better than 

control B&B trees; but fertilizer depressed growth of BR green ash, 

and there were no significant differences in growth between fertilized 

BR and B&B trees. 

During the second growing season, fertilized BR red maples produced more shoot growth than B&B 

red maples. Leaf area and weight, 

and shoot growth of BR controls 

were greater than leaf area and 

weight and shoot growth of B&B 

controls. 

In green ash, second-year response was also mixed because of 

the fertilizer-stock interaction. For 

control trees, leaf area and leaf dry 

weight were not significantly different; but BR trees had greater 

shoot, crown width, and ACD 

growth. Means for fertilized green 

ash BR trees were lower than 

means for fertilized B&B trees, although only the difference in leaf 

area was statistically significant. 

Total Crown Size 

For comparisons of total crown 

size after the two growing seasons, 

all eight treatment means were compared (Table 3). It was assumed that 

the species had equal variances. 

Fertilized BR red maples produced 

the widest crowns after 2 years, 1.65 

m-significantly wider than green 

ash in any treatment. In contrast, 

fertilized BR green ash had an average crown width of 0.84 m-significantly less than any other treatment 

of either species. However, green 

ash crowns are generally taller and 

narrower than red maple crowns, at 

least for sapling size trees; and 

when ACD was examined in a multiple comparison test, there was no 

statistically significant difference 

between the treatments, although 

fertilized BR green ash had the 

smallest ACD of all treatments. 

On-lot Versus Off-lot Growth 

The unfertilized trees on the lot 

generally grew better than the eight 

trees planted off the lot (Table 4). A 

contributing factor to the growth 

differences may have been that 

maximum soil temperatures were 

about 3°C warmer beneath the trees 

on the lot than beneath those off 

the lot (Halverson and Heisler 1981). 

There was also a difference in soil 

structure, the looser backfilled soil 

Table 3.--Mean total crown width and average crown dimension 

(ACD) after two years with results of Duncan's mean 

separation. Differences in the means of ACD were not 

statistically significant. Means with the same letter 

superscript are not significantly different. 

Treatment Mean total Mean 

crown width Treat men t ACD 

Red maple, BR, F 

Red maple, BR, C 

Red maple, B&B, C 

Red maple, B&B, F 

Green ash, B&B, C 

Green ash, B&B, F 

Green ash, BR, C 

Green ash, BR, F 

crn 

1 65d 

1 57Cd 

1 53Cd 

1 52Cd 

1 36bC 

1 35bC 

1 16b 

84a 

Green ash, B&B, C 

Green ash, BR, C 

Green ash, B&B, F 

Red maple, BR, C 

Red maple, B&B, F 

Red maple, BR, F 

Red maple, B&B, C 

Green ask, BR, F 

Table 4.-Mean height and crown width growth of trees in all four 

treatments (red maple and green ash, BR and B&B) off the 

owth of trees with the same treatments 

rences between anmlot and off-lot trees 

are significant at - 0.05. Means are in cm. 

Number Height growth Crown width 

Treatment of growth 

trees 2nd year 

1st year 2nd year 

On the lot 16 17 74 49 

Off the lot 8 1% 38 36 
in the planting holes of the lot 

being better for tree growth. The 

soil moisture measurements made 

with psychrometers during the second growing season showed no soil 

moistures below -1 bar off the lot 

and only one on the lot, but there 

may have been soil moisture differences in the O to -1 bar range 

that contributed to growth differences. 

Discussion and Conclusions 

The two species chosen, red 

maple and green ash, and the transplanting techniques used, were apparently suitable for our urban site, 

since there was no tree mortality. 

This is in contrast to experience in 

other areas where transplant mortality was high, especially with bareroot stock (Cool 1980). 

Even before the lot was built, 

the site of this study was generally 

flat and soil was moist to poorlydrained. Soil moisture was ample 

during the second season, and probably was not particularly stressful 

during the first season, although 

measurements were not made then. 

Soil moisture is generally the most 

important factor in plant survival 

and growth. 

The generally negligible response of B&B trees of both species to fertilizer indicates that addition of fertilizer to fill may not be 

effective for B&B trees, at least during the first 2 years. Roots evidently 

did not penetrate the fill to come in 

contact with the fertilizer during the 

first year. Green ash BR trees 

showed a definite negative response to fertilizer that may have 

been due to root damage caused by 

high concentrations of soil amendments. 

The fact that the fertilizer treatment was relatively ineffectual, even 

when tailored for the species as it 

was for red maple, and even on a 

moist site where fertilizer is generally most effective, suggests a 

general recommendation that fertilizer not be used at planting time. 

However, this recommendation may 

not hold for considerably impoverished soils. 

The two species produced similar-sized crowns at age 7 years on 

this site, although crown shape was 

different. Red maple tended to have 

shorter, wider crowns than green 

ash, so that when crown width and 

crown height were averaged, there 

were no statistically significant differences between species. Although 

BR trees were heavily pruned when 

planted, their faster growth made 

their crowns about equal to B&B 

crowns after 2 years. 

Heavy pruning may not be 

necessary. The reason generally 

given for it is that crowns must be 

reduced to compensate for loss of 

roots and resulting reduction in soil 

water absorption capabilities. 

Pruning should thus minimize the 

chance for severe internal water 

deficits as the new root system is 

developing. However, Whitcomb 

(1979) has suggested that pruning 

may not be necessary for some species. Bare-root transplants lifted 

from the nursery with a U-blade may 

actually retain more of the root system than trees bailed and burlapped 

(Personal communications with 

William Flemer Ill and William 

Collins, 1978). If pruning were not 

required, it would significantly reduce the already low cost of transplanting by the BR method. 

The results of this experiment 

suggest that bare-rooted saplingsize red maple and green ash trees 

may be transplanted as successfully 

as balled and burlapped stock, at 

least where moisture is not severely 

limiting. This is of considerable 

practical significance, since bareroot planting is the least costly 

method. 

Differences in soil moisture between planting sites within the 

range 0 to -1 bar may have added 

to within-treatment growth variability and obscured some treatment differences. Future experiments of this kind, with trees in isolated planting sites, should include 

detailed measurements of the entire 

range of soil moisture. 

Parking lots seem to be promising sites for establishment of urban forests with unfertilized BR 

stock. At least where good quality 

planting soil is used in adequate 

planting openings, and where soil 

moisture is ample, survival and 

growth should be excellent. 
C. H. Pham, a research associate at Rutgers University during 

the establishment of this study, provided considerable input into study 

design and assisted with first year 

measurements. He is currently with 

Westvaco, Inc. 

Literature Cited 

Cool, Robert A. Tree planting, moving, and after-care. Proceedings of 

national urban forestry conference; 1978 November 13-16; 

Washington, DC.: 1980; Syracuse, 

NY: SUNY College of Environ. Sci. 

and For. ESF Publication 80-003. 

p. 551 -558. 

Halverson, Howard G.; Heisler, 

Gordon M. Soil temperatures under urban trees and asphalt. 1981; 

USDA For. Serv. Res. Pap. 

NE-481. 6 p. 

Nelson, W. R.; Porter, J. A. Trees for 

your community. Urbana: University of Illinois; 1976; Circ. 934. 

35 p. 

New Jersey Federation of Shade 

Tree Commissions. Trees for New 

Jersey streets. New Brunswick, 

NJ: Cook College, Rutgers; 1974. 

Pham, C. H.; Halverson, Howard G.; 

Heisler, Gordon, M. Red maple 

(Acer rubrum L.) growth and foliar 

nutrient responses to soil fertility 

level and water regime. 1978. 

USDA For. Serv. Res. Pap. 

NE-412. 7 p. 

Steel, Robert G. D.; Torrie, James H. 

Principles and procedures of 

statistics. New York: McGraw-Hill; 

1960. 481 p. 

Whitcomb, Carl E. Factors affecting 

the establishment of urban trees. 

J. Arboric. 5(10): 217-219; 1979. 
Heisler, Gordon M.; Schutzki, Robert E.; Zisa, Robert P.; Halverson, 

Howard G.; Hamilton, Bruce A. Effect of planting procedures on initial 

growth of Acer rubrum L. and Fraxinus pennsylvanicum L. in a parking 

lot. Res. Pap. NE-513. Broomall, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment Station; 1982.7 p. 

Survival of 32 5-year-old red maple and green ash trees planted in holes 

in the asphalt cover of a large parking lot was 100 percent after 2 years. 

Fertilizer reduced growth of green ash planted bare-root, but had little effect on bare-rooted red maples or trees of either species planted balled 

and burlapped. Bare-rooted red maples and unfertilized bare-rooted 

green ash generally grew better than corresponding balled and burlapped trees. 

/ ODC 237.41 

Keywords: Bare-root planting, balled and burlapped planting, 

crown growth, fertilization, soil moisture, soil temperature, transplanting, tree! pruning, urban 

environment. 
Headquarters of the Northeastern Forest Experiment Station are in 

Broomall, Pa. Field laboratories are maintained at: 

@ Amherst, Massachusetts, in cooperation with the University of 

Massachusetts. 

Berea, Kentucky, in cooperation with Berea College. 

@ Burlington, Vermont, in cooperation with the University of 

Vermont. 

@ Delaware, Ohio. 

@ Dlilrhm, New Hannpltrire, in cmperation with the University of 

New Pffa~npshiire. 

0 Hamden, Connecticut, in cooperation with Yale University. 

@ Morgantown, West Virginia, in cooperation with West Virginia 

University, Morgantown. 

@ Orom, Maine, in cooperation with the University of Maine, 

Brons. 

@ Parsons, West Virginia. 

Princeton, West Virginia. 

0 Syracuse, New York, in cooperation with the State University of 

New York College of Environmental Sciences and Forestry at 

Syrac~lse University, Syracuse. 

@ University Park, Pennsylvania, in cooperation with the 

Pennsylvania State University. 

Warren, Pennsylvania.