Fall Planting of Trees and Shrubs
Curtis E. Swift, Ph.D.
Area Extension Agent (Horticulture)
Colorado State University
Planting trees and shrubs in the fall can be as successful as spring planting, if the plants are properly planted and cared for.
Fall planting has its advantages. In the fall, cells of most woody plants are lignified and suffer less stress due to water loss. Transplanting dormant trees thus reduces the demand on the plant for water (Neely, pg 7.4) For many species, research shows fall-planted trees may develop more new roots, and a greater stem diameter and plant height when compared with spring-planted trees (Hartman, et al., page 75). However, the roots of fall-planted trees and shrubs need to have a chance to grow and begin to establish before the ground freezes (Neely, page 74). Planting should be completed early enough in the fall for roots to regenerate and support the plant during the winter (Watson and Himelick, page 54). According to Harris et al., there should be at least four weeks between planting and when soil temperature drops to 40oFahrenheit (4oC). Soil temperature in the Grand Valley of Western Colordo typically drop to 40oF by November 22.
Conifers are most successfully transplanted in the fall during August and September when soil temperatures at 6-12 inches (15-30 cm) of depth are in the range of 60-70o Fahrenheit (15-21oC). (Hartman, et al., page 74). Several weeks at this temperature is especially important. New root growth must be sufficiently developed to allow water uptake to cover the loss of water from the needles during the winter. Added protection of confers by shielding these plants from prevailing winds with burlap or other suitable wind barriers may also be necessary. Antitranspirants have proven beneficial (Watson and Himelick, page 54).
The back-fill soil (the soil used to refill the hole) should be loose enough to freely allow air and water movement. It is important to improve aeration of unamended soil before using it as backfill. Break up clods and compacted soil to provide small pores without large air pockets (Hartman, page 89). If a soil amendment is needed, use a slowly decomposing organic material such as bark mulch or composted bark (Harris, page 161). Do not use sand as an amendment as this can produce a denser, less porous mixture (Harris, page 162).
Plant at the Proper Depth
Check the depth of the structural roots and plant accordingly
Drawing from Morton Arboretum Best Management Practices when planting trees
The top of the root ball is not a reliable indication of planting depth. Nursery stock may have its upper-most roots, often called the main-order roots, structural roots or root flare, anywhere from the top of ball to the middle of the ball. It is important that you remove the upper layer of soil down to 1 to 3 inches from this first tier of roots and use that level as the top of the root ball.
How to do it:
1. Always select the proper plant for the planting site. Some plants tolerate exposure to winter sun; others may die before spring unless protection is provided. Before purchasing your plants, check with a professional at a nursery or the CSU Extension office.
2. If they are not to be planted immediately, place the plants in a shady area; water them well. Cover the root system with mulch if the plant is to be kept over winter berfore planting.
Slope the sides of the planting hole.
Drawing courtesy of Maryland Cooperative Extension
3. Prepare the planting hole:
a. The planting hole should be no less than 24 inches wider than the root ball (ALCC Specifications, page 02950-7).
b. Slope the sides of the planting hole.
c. If planting into the lawn, dig the hole 2 to 4 inches shallower than the root ball depth; 2 inches for shrubs or small trees, 4 inches for large trees.
d. If planting into a shrub bed or other area where the plants can be watered separate from the turf, plant at or a little above ground level.
Note: Do NOT amend the soil below the root ball. The tree needs to sit on a firm base.If you dig the hole too deep initially, add soil and stomp it well to make a firm base.
4. Removal of Containers, Wire and Rope
1. All containers whether metal, plastic or fiber should be removed from the soil ball prior to planting.
b. "Balled and Burlapped" (B&B) plants whose soil balls are wrapped in burlap (treated or not) should have the burlap pulled away from the trunks and all restraining ropes cut and removed to prevent girdling.
c. Plants in wire baskets should have all twine around the trunks and a minimum of 1/3 of the wire completely removed before back-filling (ALCC Specifications).
5. Container-Grown Plants:
After removing the container, set the plant in the hole and score the root system to "break" the circular tendency of the roots and encourage growth into the surrounding soil. This is done by inserting a knife one inch deep into the base of the root ball and drawing the knife up to the top of the ball, cutting the roots in the process. Do this at 3 or 4 points equidistant around the ball.
6. Balled & Burlapped (B&B) Plants
a. Set the ball into the planting hole.
b. Back-fill the hole 1/3 full to stabilize the ball. Thoroughly stabilize the lower part of the root ball at planting to keep the root ball from shifting (Watson and Himelick, page 109).
c. Cut and remove any wire from the top 1/3 of the ball.
d. Roll the burlap down to the base of the plant if possible, slash it with a knife, or remove it from at least the top third of the root ball (Watson and Himelick, page 111).
Note: Remove any twine or wire found around the trunk or stem(s) of the plant (Watson and Himelick, page 111).
7. Water thoroughly while back-filling to avoid leaving air pockets.
a. The back-fill can be tamped firmly around the base of the root ball to stabilize it, but the rest of the soil should be only lightly tamped (Watson and Himelick, 114).
b. Do NOT stomp or pack soil as this forces oxygen out of the soil causing root death.
c. Avoid walking over the amended area.
Note: Trees and shrubs going into the winter with dry soil around their roots, especially when a dry fall is followed by a cold winter, are more susceptible to dying by spring (Hartman, et al., page 75).
8. Wait a year or more after planting to fertilize unless the soil is nutrient deficient (Watson and Himelick, page 128). Research on field nursery trees indicates there is no benefit to fertilizing at planting (Gilman, page 77.)
Note: Do NOT place fertilizer tablets in the back-fill soil.
9. Stake only when necessary!
a. On certain soils, on windy sites, when trees and shrubs are quite large, or when planting collected aspen, staking may be required.
b. Use canvas, nylon straps or strips of indoor-outdoor carpet (several inches wide) around tree to protect the bark. If indoor-outdoor carpet is used place it with the carpet side next to the bark.
c. Attach guy wires to the loose ends of the strapping material (see diagram).
Note: Do NOT place guy wires around trunk.
Note: Do NOT use hose (threaded with guy wire) around the trunk.
10. Only diseased or broken branches should be removed (Hartman, page 92). Do not cut into healthy tissue as this could increase moisture loss and result in internal trunk damage.
Note: Do NOT shear fall-planted shrubs.
11. Keep grass and weeds away from young trees and shrubs.
a. Clear a 2 to 3 foot diameter circle around each newly planted tree and apply a 2-4 inch layer of bark mulch. A smaller, mulched area is recommended for shrubs.
b. Mulch helps keep the soil warmer longer, allowing the roots more time to establish.
Note: Keep mulch several inches away from the trunk to avoid trunk rot (Gilman, page 76).
Note: Do NOT place black plastic below the mulch. A woven landscape fabric can be used as a weed barrier if desired.
12. Additional Watering Requirements:
a. Rewater the plant several hours after planting to help settle the soil around the root ball and eliminate air pockets.
b. Water thoroughly again in a week to 10 days if needed.
c. Do NOT drown the roots by watering too often.
d. Soak the new plants monthly during the winter. Water when air temperature is above freezing and early enough in the day to allow the water to soak in by night fall.
13. Wrap newly planted deciduous trees (trees that lose their leaves) with a standard crepe wrap on or about November
a. Start at the base and overlap the wrap as you spiral the material up overlapping 50%. Wrap up to the first limb or higher if possible.
b. Remove the wrap the following spring (~ April 1) (ALCC Specifications Handbook).
Note: Do NOT use twistems, wire or twine to secure the wrap.
14. When you fertilize, this should be accomplished between bud-break and the middle of July. Trees in lawns may not need additional fertilizer. In other areas, a soil analysis is recommended. Call or visit the CSU Extension office for further information.
Guy trees properly
for more information check out the web page on guying trees
ALCC Specifications Handbook for Landscape/Irrigation Installation and Maintenance Contracting. 1996. Associated Landscape Contractors of Colorado, Inc. Denver, CO.
Gilman, E. F. 1994. Establishing trees in the Landscape. Pages 69-77 in: The Landscape Below Ground: Proceedings of an International Workshop on Tree Root Development in Urban Sites. Watson, G.W. and Neely, D., eds. International Society of Arboriculture. Savoy, Ill.
Harris, J.R., Knight, P., and Fanelli, J. 1996. Fall transplanting improves establishment of balled and burlapped fringe tree (Chionanthus virginicus L.). HortSci. 31:1143-1145.
Harris, R.W. 1992. Arboriculture: Integrated Management of Landscape Trees, Shrubs and Vines; Second Edition. Prentice Hall. Englewood, Cliffs, NJ.
Hartman, J.R., Pirone, T.P., and Sall, M.A. 2000. Pirone's Tree Maintenance; Seventh Edition. Oxford University Press.
Neely, D., ed. 1993. Arborists' Certification Study Guide. International Society of Arboriculture. Savoy, Ill. Watson, G.W., and Himelick, E.B. 1997. Principles and Practice of Planting Trees and Shrubs. International Society of Arboriculture. Savoy, Ill.
Placed on the Internet October 12, 2002; updated March 5, 2010