Arbor Day: Do’s and don’ts of tree planting

Published 10:26 am Tuesday, May 7, 2019

In observance of Arbor Day celebrated April 26, we will talk about how to properly plant and care for trees. This two-part series is adapted from an article in the Northern Virginia SWCD newsletter by Jim McGlone, Urban Forest Conservationist for the Virginia Department of Forestry. Keep a look out for the second part of this article to be published next month.

Emily Gibbs

Unless you are planting a tree from a seed, your new tree will experience transplant shock. Transplant shock is the stress that a tree experiences when it is transplanted from one location to another. McGlone of the Virginia Department of Forestry says, “transplant shock occurs when newly planted tree roots cannot supply enough water to the newly planted leaves and it lasts until the roots and crown are back in balance.” So how do the roots and crown get out of balance? Trees are always growing and shedding fine roots, which collect water and nutrients from the soil. The fine roots grow on the larger, connective roots that provide structure for the tree to remain stable. A tree will usually grow and shed more fine roots than leaves (which make up the crown of the tree); however, this process is thrown off balance when a tree is transplanted. Thus, transplant shock will last until the tree can produce enough fine roots to supply sufficient water to the leaves.

Why is transplant shock an important factor? According to the Purdue University Cooperative Extension Service, “It involves failure of the plant to root well … New transplants do not have extensive root systems, and they are frequently stressed by lack of sufficient water. Plants suffering from water stress may be more susceptible to injury from other causes such as the weather, insects or disease. When several stresses are being experienced, the plant may no longer be able to function properly.”

To minimize transplant shock, choose a bare root seedling, which usually has a healthy balance between the roots and crown. Bare root seedlings regrow their fine roots quickly, so transplant shock does not last as long and is not as severe. Typically, larger trees, when transplanted, have a more significant imbalance between the roots and crown, so they experience longer and more serious transplant shock. According to McGlone, “(A) 4 inch caliper [measure of diameter] balled and burlapped sapling may lose 85-90 percent of its roots when it is dug up and will require years to recover … Until trees recover from transplant shock, they will spend all their energy growing roots. Because of this, bare root seedlings usually catch up to larger stock trees in much less than 10 years.”

However, if you choose a larger tree instead of a bare root seedling, make sure that the hole you dig is large enough for the tree. Consult a nursery or greenhouse for guidance on this. An especially important factor is giving the tree enough water. The University of Minnesota Extension Service recommends giving 1-1.5 gallons of water per inch of stem caliper (width/diameter of stem). As the tree grows, the amount of water will need to be increased. According to the Morton Arboretum, “[Water] within the drip line of the tree, from the trunk out to the end of the branches, to reach the roots most effectively. The water-absorbing roots are within the top two feet of soil; you want to keep these roots moist but not wet.” Continue to regularly water the newly planted tree until it has gone through two growing seasons.

EMILY GIBBS is the residential conservation and marketing coordinator at Piedmont Soil & Water Conservation. You can contact her at (434) 392-3782 ext. 131 or visit www. piedmontswcd.org.