Tree Establishment
The length of time for the establishment of a tree depends on the original tree size and the growing conditions after planting. All trees experience transplant shock regardless of tree size when planted. During the period of transplant shock, both root and shoot growth are reduced. Vigorous growth does not return until the roots are established. With proper care, a 1-inch diameter tree (measured at chest height) should develop an established root system by the end of the first year, while a 4-inch diameter tree requires a minimum of 5 years.
Mulching
Mulch retains soil moisture and moderates soil temperature extremes. A 2- to 4-inch layer applied out to the tree’s drip line is ideal. More than a 4-inch mulch depth can cause problems with oxygen and moisture levels. Avoid mulch “volcanoes.” Keep mulch a few inches away from the trunk to avoid pest and disease problems. Mulch provides a well-cared for appearance, while preventing damage from lawn care equipment.
Fertilization
Fertilizer and/or lime should be applied based on soil test results. Fertilization is not a “cure-all” for declining trees but may be used to complement other tree maintenance activities. Younger trees benefit more from fertilization than older trees. In early spring, broadcast a slow-release fertilizer evenly over mulched and unmulched surfaces in the root zone area (out to 1.5 times the canopy radius). Fertilizer should always be applied to moist soil to improve uptake and to reduce the chance of root injury. Improper fertilizer type, rate, and application can injure plants.
Construction Damage
Protect the tree roots from soil compaction, paving, or mechanical damage. Remember that tree roots extend 2 to 3 times the width of the canopy. Roots are required for structural stability and for supplying water and nutrients. The amount of damage a tree can suffer from root loss depends on how close the cut is made to the trunk. Severing one major root can cause a loss of 5-20% of the root system.
Insect & Disease Monitoring
Monitor for insect and disease problems regularly and treat only if necessary. Some can damage or kill trees, but many do not pose a significant threat to tree health or require treatment. By first identifying the problem, you can determine if any treatment is necessary.
Tree & Turfgrass Root Competition
Turfgrass roots colonize the top 2- to 3- inch layer of soil while tree roots are concentrated in the top 6 to 12 inches of soil. Because of these root depths, trees and turfgrasses compete for the same soil nutrients and moisture. Turfgrass may compete more successfully than the tree for water and nutrients, especially if established before the tree. Mulching eliminates some of this competition by allowing only the tree to use the nutrients and water applied under the tree. Most turfgrasses do not grow well in the deep shade anyway.
Pruning
Pruning is not necessary for the first year after planting. Structural pruning should be done every 2 to 3 years, beginning in the second season and ending in the tenth year after planting. This will establish a strong and sturdy trunk with well-spaced branches, 12 to 18 inches apart. Trees that receive appropriate pruning while young will require little corrective pruning at maturity.
Never top trees. Topping is detrimental to both the natural appearance and overall health of the tree. If a mature tree needs pruning, always contact a certified arborist.
Irrigation
Lack of water is often the cause of poor tree health and growth. Irrigate established trees at the first sign of wilting or when the top 12 inches of soil is dry. A slow soaking over several hours is best and may be done with a low-pressure sprinkler or soaker hose, starting at the trunk and extending beyond the furthest branch spread. Avoid overwatering as too much water can kill a tree by eliminating the air from the soil.
For the poster version of this document, see Tree Maintenance Poster.
Reference:
- Prendergast, D. and E. Prendergast. 2017. The Tree Doctor: A Guide to Tree Care and Maintenance. 2nd Edition. Firefly Books, Inc., Buffalo, NY. 160 p.
Originally published 01/21