Planting Trees and Shrubs
7 September 2008
Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578
Fall is a good time to plant trees and shrubs. If you choose to do so please consider following some basic planting guidelines. You can save yourself and your plants some trouble down the road. The cornerstones of successful tree or shrub planting are plant and site selection, site preparation, plant preparation, and care after planting. Begin by selecting trees and shrubs that are well adapted to conditions of individual planting sites. Poorly sited plants are doomed from the start, no matter how carefully they are planted.
Test your soil drainage before planting. Dig a test hole as deep as your planting hole and fill with water. If water drains at a rate of less than one inch per hour, consider installing drainage to carry water away from the planting hole base, or moving or raising the planting site. Also consider using more water-tolerant species. For trees, try red maple, sycamore, bald cypress, willow oak, or river birch. For shrubs, try inkberry, red twig dogwood, and buttonbush. Avoid other dogwood species, azaleas, boxwoods, Japanese hollies, and other plants that do not like "wet feet" where drainage is poor.
Examine soil for compaction before planting. If soils are compacted, consider replacement with a good loam soil, or incorporating several inches of an organic material such as composted yard waste to a depth of at least 8 inches over the entire planting area. Do not incorporate small quantities of sand because compaction will increase and drainage will decrease.
Dig shallow planting holes two to three times as wide as the root ball. Wide, shallow holes encourage horizontal root growth that trees and shrubs naturally produce. In well-drained soil, dig holes as deep as the root ball. In poorly drained heavy clay soil, dig holes one to two inches shallower than the root ball. Cover the exposed root ball top with mulch.
Do not dig holes deeper than root balls or put loose soil beneath roots balls because loose soil will compact over time, leaving trees and shrubs planted too deep. Widen holes near the soil surface where most root growth occurs. Score walls of machine-dug (auger, backhoe) holes to prevent glazing.
Backfill holes with existing unamended soil. Do not incorporate organic matter such as peat moss into backfill for individual planting holes. Differences in soil pore sizes will be created causing problems with water movement and root growth between the root ball, planting hole, and surrounding soil. Backfill half the soil and then water thoroughly to settle out any air pockets. Finish backfilling and then water again. Cover any exposed root ball tops with mulch.
Incorporate slow-release granular fertilizers into backfill soil to provide nitrogen or if a soil test indicates a need for phosphorus or potassium. Avoid using fast-release agronomic fertilizers that can dehydrate tree roots. Use no more than 1 pound actual nitrogen per 1,000 feet of planting hole surface.
Closely inspect the wrapping around root balls of B&B (balled and burlapped) trees and shrubs. Growers use many synthetic materials, as well as burlap treated to retard degradation, to wrap root balls. Many of these materials will not degrade. To insure root growth into surrounding soil, remove pinning nails or rope lacing, then cut away or drop the wrapping material to the bottom of the planting hole, remove it if possible, backfill over it if not.
Wire baskets used to protect root balls degrade very slowly underground. Remove at least the top 8-12 inches of wire to keep equipment from getting caught in wire loops, and surface roots from girdling. Remove all rope, whether jute or nylon, from trunks. Again, degradation is slow or nonexistent, and ropes can girdle trunks and roots.
Remove plastic containers from container-grown trees and shrubs. For plants in fiber pots, break away the top or remove the pot entirely. Many fiber pots are coated to extend their shelf life, but this slows degradation below ground and retards root extension.
If roots are circling around the root ball exterior, cut through the roots in a few places. Cutting helps prevent circling roots from eventually girdling the trunk. Select trees grown in containers with vertical ribs or a copper-treatment on the interior container wall. These container modifications and treatments minimize circling root formation.
Remove tags and labels from trees and shrubs to prevent girdling branches and trunks. Good follow-up watering helps promote root growth. Drip irrigation systems and water reservoir devices can facilitate watering.
Mulch, but do not over mulch newly planted trees and shrubs. Two to three inches of mulch is best. Use less if you are using a fine material, more if the material is coarse. Use either organic mulches (shredded or chunk pine bark, pine straw, composts) or inorganic mulches (volcanic and river rocks). Keep mulch from touching tree trunks and shrub stems. This prevents disease and rodent problems if using organic mulches, and bark abrasion if using inorganic mulches.
Only stake trees with large crowns or those situated on windy sites or where people may push them over and stake for a maximum of one year. Allow trees a slight amount of flex rather than holding them rigidly in place. Use guying or attaching material that will not damage the bark. To prevent trunk girdling, remove all guying material after one year.
Most trees should not have their trunks wrapped. Wrapping often increases insect, disease, and water damage to trunks. Thin-barked trees planted in spring or summer into hot or paved areas may benefit from wrapping if a white wrap is used. To avoid trunk girdling, do not attach wraps with wire, nylon rope, plastic ties, or electrical tape. If wraps must be used, remove within one year. For protection against animal or equipment damage, install guards to protect the trunk. Be sure the guards are loose fitting and permit air circulation.
For more information about this and other landscape topics contact your local Virginia Cooperative Extension office. The local Virginia Cooperative Extension office numbers are Albemarle 872-4580, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.