The first 2 or 3 years are the most important period in the establishment of newly planted trees. Good cultural practices during this period help reduce transplant stress and create a favorable environment for tree growth.
The key to watering newly planted trees is to check the moisture status of the plant s root-ball or root-mass. The roots of newly planted trees are initially confined to the plant s root-ball (balled and burlapped trees) or root-mass (container-grown plants). Newly planted trees should be watered when the root-ball or root-mass (not the surrounding soil) begins to dry out. Frequently check the moisture status of the root-ball or root-mass as it can dry out quickly. To water the root-ball or root-mass, slowly apply water to the base of the tree. The frequency of watering can be reduced and the watering area enlarged as the tree s root system begins to grow into the surrounding soil. Small trees usually require watering for 1 or 2 growing seasons. It may be necessary to water large trees for 3 or 4 years.
To help conserve moisture, place 2 to 4 inches of mulch, such as wood chips or shredded bark, around trees. Mulches also help control weeds, moderate soil temperatures, and reduce the risk of mechanical damage to tree trunks from errant lawnmowers and string-trimmers.
When mulching trees, do not place mulch against the tree s trunk. Keep the mulch at least 6 inches away from the trunk of the tree. Mulch piled against the tree trunk may create favorable conditions for fungal cankers, root rots, insects, and rodents.
It is generally not necessary to fertilize newly planted trees. Most Iowa soils can supply sufficient amounts of nutrients during establishment. If the trees are growing poorly 2 to 3 years after planting, fertilization may be beneficial. Poorly growing trees often exhibit sparse foliage, yellow-green leaves, or short annual twig growth.
Trees utilize sugars and other carbohydrates manufactured by the foliage for plant growth. Therefore, avoid the temptation to severely prune newly planted trees. Severe pruning reduces the tree s ability to manufacture food and actually slows plant growth. Newly planted trees require only corrective pruning. Remove structural defects, such as double leaders and dead, broken, or crossing branches. Retain most of the lower branches to help stabilize the tree. The lower branches also provide food for the growing tree. Gradually remove the lower limbs as the tree grows during the first 5 to 10 years.
Staking is not required for most newly planted trees. However, top-heavy trees and those planted in windy, exposed sites may require staking. If staking is necessary, allow the trunk to move or sway for proper trunk and root development. To prevent damage to the trunk, use strong, wide strips of canvas, rubber, or other materials to support the tree. Remove the stakes as soon as possible. Stakes can often be removed after one growing season.
Wrapping protective materials around the trunks of newly planted trees is usually not necessary. There appears to be little or no benefit to tree wraps. If you do decide to use a tree wrap, place it around the tree in fall (November) and promptly remove it the following spring (April).
Newly planted trees do require special care during establishment. However, the rewards for our efforts are healthy, attractive trees which will provide us with many years of enjoyment.
This article originally appeared in the April 19, 2002 issue, p. 46.