Search Results

You are looking at 1 - 10 of 34 items for

  • Author or Editor: J. Roger Harris x
Clear All Modify Search
Free access

Growth and physiological responses before and after transplanting to a simulated landscape were studied for `East Palatka' holly (Ilex ×attenuata Ashe `East Palatka') grown in plastic containers (PC), in the ground in fabric containers (FC), or in the ground conventionally. At the end of a 15-month production period, trees grown in PC had more shoot dry weight and leaf area than trees grown in FC, and they had thinner trunks than field-grown trees. Root balls on harvested field-grown trees contained 55% and those grown in FC 65% of total-tree root surface area. Trees transplanted from FC had the lowest predawn leaf xylem potential and required more frequent post-transplant irrigation than trees grown in PC or in the ground. Carbon assimilation rate and stomata1 conductance in the first week after transplanting were highest for trees planted from PC. Dry weight of regenerated roots was similar for all production methods 4 months after transplanting from the nursery, but trees grown in PC had SO% more regenerated root length, and the roots extended further into the back-fill soil.

Free access

Root flares of landscape trees are increasingly found to be much deeper than their forest counterparts, indicating that their root systems have been situated deeper in the soil. Planting deeply in production containers contributes to this phenomenon, yet the consequences of deep planting in production containers or the consequences of any adjustments made to planting depth at the time of transplant on growth in the landscape have not been reported for many species. Container-grown (11.4 L) liners of Tilia cordata Mill. (littleleaf linden) and Quercus palustris Münchh. (pin oak) were planted in 50-L containers with the first main lateral roots (structural roots) at substrate-surface grade or 10 cm or 20 cm below grade (deep planting). Trees were grown in the 50-L containers for two growing seasons and in a simulated landscape for three additional seasons after transplanting with the top of the container substrate at soil level or with some roots and substrate removed such that the original structural roots were just below the soil surface (remediated). Deep planting pin oak, but not littleleaf linden, slowed growth during container production; however, the effect did not persist after transplanting. Remediation of the 20-cm-deep pin oaks slowed growth during all three post-transplant years. Littleleaf linden remediation slowed growth for the first season after transplanting to a simulated landscape for 10-cm-deep trees and for the first two seasons for 20-cm-deep trees. Evaluation of pin oak root systems 3 years after transplanting revealed vigorous growth of non-deflected adventitious roots that had formed on the trunks of deep trees, and these roots appeared to be developing into main structural roots. No adventitious roots were present on littleleaf linden; instead, deflected roots grew and produced deformed root systems. Deep planting of linden reduced suckering; however, we conclude that remediation of deep-planted littleleaf linden is warranted as a result of potential hazards from trunk-girdling roots. In some species such as pin oak, non-deflected, strong adventitious root systems may assume the role of structural roots and diminish the effect of deflected and circling roots systems formed during container production. Remediation of these trees is likely not as critical as for species without abundant adventitious roots.

Free access

Prudent landscape professionals can enhance chances for successful establishment by timing tree transplant operations to coincide with ideal seasonal conditions. However, transplant timing is usually determined by economic factors, resulting in trees being transplanted at times that are unfavorable for their survival and growth. Knowledge of the effects of season of transplanting on the establishment of landscape trees can help assure the highest probability of success, especially since special post-transplant management may be required if trees are transplanted at unfavorable times. This manuscript reviews past and current research on the effects of transplant timing on landscape establishment of deciduous shade trees. Specific results are summarized from several key studies.

Full access

The effect of fall vs. spring transplanting was tested on landscape-sized Chionanthus virginicus L. at a research farm in Blacksburg, Va. Two fall transplanting dates (11 Nov. and 1 Dec. 1994) were selected so that soil temperatures were decreasing and near 10 °C for the earlier fall date (11 Nov.) and decreasing and near 5 °C for the later fall transplanting date (1 Dec.). The spring date (14 Mar. 1995) was selected so that soil temperatures were increasing and near 5 °C. All trees were transplanted with rootballs of native soil wrapped in burlap (B&B). Fringe tree was clearly tolerant of fall transplanting. Trees transplanted on 11 Nov. had a larger leaf area 1 month after bud set the next summer and had wider canopies and more dry mass of new roots at leaf drop than trees transplanted on the other dates. Trees transplanted on 14 Mar. had less total leaf area, leaf dry mass, and lower maximum root extension into the backfill soil than trees transplanted on 11 Nov. or 1 Dec. No root growth occurred beyond the original rootball until about early July (1 month after bud set) in any treatment, suggesting that first season posttransplant irrigation regimes need to focus on rootballs, not surrounding soil areas.

Free access

Rapid posttransplant root growth is often a determining component of successful establishment. This study tested the effect of transplant timing on first-season root growth dynamics of bare-root Turkish hazelnut trees. Trees were either harvested and planted in the fall (F-F), harvested in the fall and planted in the spring after holding in refrigerated storage (F-S), or harvested and planted in the spring (S-S). All trees were transplanted into 51-L containers, adapted with root observation windows. Root growth began in F-F and F-S trees 1-2 weeks before spring budbreak, but was delayed in S-S trees until ≈3 weeks after budbreak. Budbreak was 6 days earlier for fall-harvested than for spring-harvested trees. No new roots were observed before spring. Root length accumulation against observation windows (RL) was delayed for S-S trees, but rate of increase was similar to F-F and F-S trees soon after growth began. Seasonal height, trunk diameter growth, and RL were similar among treatments. Surface area of two-dimensional pictures of entire rootballs was not correlated with seasonal RL.

Free access

Description of early post-transplant root growth will help formulate best transplanting strategies for landscape trees. In this experiment, the dynamics of early root system regeneration of sugar maple (Acer saccharum Marsh. `Green Mountain') and northern red oak (Quercus rubra L.) were determined. Field-grown 4-year-old trees were transplanted bare-root into outdoor root observation containers (rhizotrons) in Oct. 1997, Nov. 1997, or Mar. 1998. All trees were grown in the rhizotrons until Oct. 1998 and then transplanted, with minimally disturbed rootballs, to field soil and grown for an additional two years. October-transplanted trees of both species began root regeneration earlier and regenerated more roots, as judged by accumulated root length on rhizotron windows, than Nov.- or March-transplanted trees. Median date for beginning root extension for sugar maples was 48, 22, and 0 days before budbreak for October-, November-, and Marchtransplanted trees, respectively. Median date for beginning root extension for northern red oak was 4, 21, and 14 days after budbreak for October-, November-, and Marchtransplanted trees, respectively. Height and trunk diameter growth were similar for all treatments within each species for 3 years after application of treatments. Early fall transplanting will result in earlier first season post-transplant root growth for sugar maple and northern red oak. Earlier post-transplant root growth will likely increase resistance to stress imposed by harsh landscape environments.

Free access

Two rootball sizes as well as a nontransplanted control were randomly assigned to Acer saccharum Marsh. (sugar maple) trees in four adjacent nursery rows at Waynesboro Nurseries in Waynesboro, Va. One size (75 cm in diameter) corresponded to the American Association of Nurserymen standards. The other rootball size was 90 cm in diameter. Trees were transplanted just before bud swell or during shoot elongation. Rootball size had no effect on height, stem diameter, or twig growth, total nonstructual leaf nitrogen content (LNC), or total stem nonstructual carbohydrate (TNC). Height growth was reduced by 81%, stem diameter growth by 71%, and twig growth by 82% for trees transplanted before bud swell compared to nontransplanted trees. LNC was 25% more on transplanted trees than on nontransplanted trees, presumably due to a dilution effect. TNC was 20% higher on transplanted compared to nontransplanted trees. Growth was severely curtailed on late-transplanted trees for all characteristics measured compared to all other treatments.

Free access

Seasonal effects on transplant establishment of balled-and-burlapped (B&B) shade trees are not well documented. Early post-transplant root growth and above-ground growth over 3 years were therefore documented for November- and March-transplanted northern red oak (Quercus rubra L.) and willow oak (Q. phellos L.). Survival of red oak was 100% for both treatments. Survival of November- and March-transplanted willow oak was 67% and 83%, respectively. No new root growth was observed outside or within the root balls of either species upon excavation in January. However, new root growth was evident when subsamples were excavated the following April for November-transplanted trees of both species, indicating that root system regeneration of November-transplanted trees occurs in late winter and/or early spring, not late fall and/or early winter. November-transplanted red oak, but not willow oak, had grown more roots by spring bud break than March-transplanted trees. While height growth of willow oak was nearly identical between treatments after 3 years, November-transplants exhibited greater trunk diameter increase for all 3 years. Overall, season of transplant had little effect on height and trunk diameter increase of red oak, even though November-transplanted trees grew more roots prior to the first bud break following transplant. Among the willow oaks that survived, season of transplanting had little effect on height growth, but November transplanting resulted in greater trunk diameter increase. However, considering the mortality rate of November-transplanted willow oak, March may be a better time to transplant willow oak in climates similar to southwest Virginia.

Free access

Humate-based products have been aggressively marketed as biostimulants that increase plant growth. Little data are available on their effect on tree establishment or their interaction with fertilizer and irrigation regimes. This experiment tested several types of biostimulants on posttransplant growth of Acer rubrum L. (red maple) and Crataegus phaenopyrum (Blume) Hara (Washington hawthorn) trees, both with and without irrigation and fertilization. Soil treatments were applied at planting as: 1) control (native backfill only); 2) compost (native backfill + yard-waste compost); 3) peat (native backfill + Canadian sphagnum peat); 4) granular humate, 100 g/tree; 5) granular humate, 200 g/tree; and 6) liquid humate +, a proprietary liquid mixture of humate, kelp extract, thiamine, and intermediate “metabolites.” Irrigation regime × soil treatment interaction was significant for red maple, but soil treatments did not increase height, stem diameter, top dry mass, or root length. For Washington hawthorn, soil treatments did not increase height, stem diameter, or root length, but top dry mass in all treatments as a group and in humate-treated trees in particular was greater than that of controls. Roots of peat-treated trees of both species were longer than those in other treatments. Granular humate applied at 200 g/tree increased total root length more than did 100 g/tree in Washington hawthorn but not in red maple. Fertilizing at planting with N at 14.5 g·m-2 had no effect on any parameter measured for either species.

Full access