Post-planting Tree Care
by Michael Kuhns, Extension Forestry Specialist
Many trees were planted in Utah this spring. Though trees generally do a good job of taking care of themselves after planting, some care is needed to ensure the their quality and health for the future.
Trees should be watered thoroughly at planting time and once a week (corrected for significant rain) through the first growing season. Water more often on sandy soils or during very hot, dry weather. A light sprinkling that only wets the soil surface is not enough. Water must penetrate 6 to 12 inches to reach most of the tree's roots and to encourage deep rooting. If irrigation water is limited this summer due to drought, be sure to give adequate water to your trees or they may decline in health and die. Lawn that dies due to lack of water can be replaced fairly quickly; trees cannot.
Stake newly-planted trees that are over 2 to 4 feet tall if they will catch a lot of wind. Trees should be staked loosely, however, since some bending is needed for the trunk to develop naturally. Anything that wraps around the trunk, like wires or cords, should be well-padded to avoid damaging the tree's bark and outer growing layers. Stakes should be removed after 1 or 2 years. If the root system is not well-established by then it is not likely to become established.
Mulching newly-planted trees and established trees is one of the best ways to ensure their health. A 4 foot or larger circle of wood chips, compost, or other coarse organic mulch 4 inches deep helps control weeds, keeps roots moist, reduces soil compaction, and keeps the mower away from the tree's trunk. If turf is already established around the tree place the mulch directly on the turf. Any grass not shaded-out by the mulch can easily be pulled.
Fertilization is not necessary for most trees and no fertilization should be done at planting time or for at least a year or two after planting. If fertilization is to be done, wait until twig growth has returned to a normal rate. This indicates that the tree is no longer suffering from transplanting shock. Use a complete, granular fertilizer spread on the surface under the tree's crown and water it in well. Avoid using "weed-and-feed" fertilizer-herbicide combinations around trees since these are designed to avoid injuring grass but may damage trees.
Follow these steps and keep an eye out for insect and disease problems and your new tree will give you years of enjoyment.