Consider these tips for tree selection, planting

March 31, 2019

If planting a tree this spring, keep diversity in mind and know what common mistakes to avoid when planting and caring for trees.

Tree species diversity is a measure of community forest health. Community forests are comprised of trees growing in parks, along streets, and in home and business landscapes. In rural areas, they are trees found in windbreaks and shade trees on farms and acreages. As the Nebraska Forest Service says, increasing diversity prevents us “putting all our eggs in one basket.” This helps prevent a single insect or disease from destroying a significant portion of a community forest.

Dutch elm disease, pine wilt, and the approaching emerald ash borer reinforce the importance of tree diversity in communities. Consider planting something different from what is commonly found in your area.

For help in selecting trees, ask for recommendations at a local nursery or garden center or at a Nebraska Extension office. Another source is the Nebraska Forest Service who provides a list of trees to plant. They are trees that grow well here but tend to be underused.

Go to nfs.unl.edu and scroll down and click on Trees to Plant. An additional source is the Nebraska Statewide Arboretum. They have many listings of trees for Nebraska, such as “Best Trees to Replace Ash.” Go to plantnebraska.org/plants/ for these suggestions.

Once the right tree is selected, be sure to plant it right. There are common planting mistakes made and if trees could talk, they would say “don’t plant me too deep; don’t fertilize me with nitrogen at planting; give me lots to drink, but don’t drown me; and, don’t cut off my branches at planting.”

Too deep of planting is a common killer or stressor of trees. After planting, the trunk taper at the base of the trunk, where the trunk flares slightly, should be visible above ground. When digging the hole, never loosen the soil beneath the soil ball or the tree will settle and end up too deep. Dig a wide, shallow hole.

As for applying nitrogen at planting, most Nebraska soils are fertile enough to support trees. It is uncommon for trees to need nitrogen fertilizer at planting, or most any other time if they are growing in a fertilized lawn. At planting, nitrogen forces growth at a time when the tree is stressed from transplanting.

While the soil of newly planted trees needs to be kept uniformly moist, it is equally important not to overwater. Healthy roots grow when there are about equal amounts of moisture and oxygen in the soil. Over watering reduces soil oxygen, leading to slow root growth and can result in root rot. Pruning is not recommended at planting except to remove a double leader or broken branches. There is stored food in branches, and green tissue for photosynthesis, which the trees need to recover from transplant shock. Avoid pruning newly planted trees until a few years after planting.