Choosing a Healthy Tree or Shrub
by Don Janssen, Extension Educator
For many people, selecting a healthy tree or shrub is a game of chance. Sometimes you win, occasionally you lose. By following the suggestions listed below, the odds of selecting a healthy tree or shrub can be shifted in your favor.
Look for signs of good health. Avoid plants that appear wilted or have off-color foliage. These are signs that care has not been optimal or something may be wrong with the root system. Desirable trees possess good foliage color and full-sized leaves. Leaves should be pliable yet firm. Select trees with a well developed leader and straight trunk. Branches should be well spaced and evenly distributed on all sides of the leader.
When looking at trees in early spring, most deciduous trees will be dormant. Scraping the bark of a live branch with a fingernail should reveal green tissue beneath. If not, the branch may be dead. Check other branches to determine the status of the tree. Live branches are quite flexible for most plant species. A dead branch will snap and break. Buds, present since last summer, should be swollen and plump. The tree's previous growth can be checked by observing the bud scars on the branches. Very little growth between scars (less than 4 inches) is a sign of a tree in trouble. Check the trunk for mechanical injury, environmental injury such as sunscald, or animal damage. Trees with obvious disease and/or insect problems should be avoided as well.
The top of the tree isn't the only area that needs checking prior to purchase. The root system is important as well. Many trees are sold in containers or balled and burlapped (B&B). Avoid trees which appear too large for their container. This may be an indication that the tree is pot bound. Pot bound trees and shrubs are not healthy plants. Pot bound trees often develop circling roots which, left uncorrected, can eventually girdle or choke the tree. At planting, cut the root system vertically at regular intervals at the outer edge of the soil ball and pull the root system apart. This will encourage the formation of new roots which will spread into the surrounding soil. Often plants will be shifted to a larger container. This helps if the roots were properly cut prior to repotting. Repotted plants that are not root pruned may appear healthy but really are not. Check for soils of different consistencies or remnants of a fiber pot as indicators of trees that have been shifted up.
To check for well-rooted plants, grasp the trunk of the tree near the base and try to move the tree in the container. Well-rooted plants should not create a hole in the soil when the stem is shaken. The container and the tree should move as one. Containerized plants can be removed (properly) from the container and the root system examined without harming the tree. Healthy roots are firm and usually lighter in color than the surrounding soil. There should be no offensive odor or mushiness. Ask a nursery employee for permission and/or assistance before pulling the plant from its container. Carry trees by their container or root ball rather than by their trunks to avoid damaging their root systems. B&B trees are checked much the same way as a containerized tree. The ball should not have cracks in the soil or large clumps of loose soil. If it does, these are indications of improper handling which could mean trouble later on.
Buy nursery stock from reliable nurseries which are knowledgeable about the plants they sell, offer plant guarantees, and practice proper handling and care of their nursery stock. Avoid being a home for wayward plants even though the price is right. Be a wise consumer and research the plant before purchasing to find out its adaptability to your location and cultural requirements. Quiz the nursery staff and see if they can answer your questions sufficiently, remembering that they are in the business of selling.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office