Planting and Care of Trees
More trees die due to our mistakes in planting and care than from diseases and insects. The most common cause of a young tree dying is planting it too deeply. Aftercare is also important, it takes about three years for a newly planted tree to be able to survive on its own.
Planting: Recommendations as to how to plant a tree vary according to the soil type. In good loamy soil or in sandy soil, the tree can be planted at the same level is was in the container. However, in clay soil, the tree should be planted 2-4 inches above surrounding grade, in order to improve drainage. Dig no deeper than needed to plant the tree; the root ball needs to be on native solid ground to prevent sinking when soil settles. The hole should be 2-3 times the diameter of the root ball.
Amendments: Do not add amendments to the native soil used to refill the hole. Doing so will encourage the new roots to stay in the hole and not extend into surrounding soil. Adding a slow release fertilizer to the soil at the time of planting is optional.
Staking: Not all trees need staking. If they are on an incline, in a windy area, or if after planting, the tree seems unstable stake it. Use two stakes applied to protect from the direction of prevailing wind. The bindings should be loose and the stake removed after one growing season.
Mulching: All trees benefit from mulch. The mulch should be loose, to allow water and air circulation. No one type is better than another. Mulch will prevent weeds, conserve water, moderate extremes of temperature and prevent damage from lawn equipment. It has been shown that if you mulch to prevent turfgrass from growing over the root zone of young trees, the rate of growth may be up to three times that of unmulched trees.
Irrigation: Irrigate thoroughly at the time of planting and keep the soil moist for the next few weeks. After that, most young trees need 1-2 inches of water per week. It takes about three years for the new tree to develop a root system allowing it to be independent.
Fertilization: Young trees should be fertilized annually. Established trees, especially it the root zone extends into a lawn which is regularly fertilized, may not need fertilizer. Fertilizer can be applied in the fall after the first frost and in the spring. What type of fertilizer to use is best based on a soil test. How much to be used, especially for mature trees can be a bit complicated. Consult the reference below for details.
HLA-6412: Fertilizing Shade and Ornamental Trees and Shrubs