Protecting Newly Planted Trees
Even though the drought of 2011-2015 is on its way to being a rarely mentioned historical event, our trees are still suffering the consequences and we will likely continue to lose more than normal over the next several years. We need to continue to plant young trees with the assumption that some of our older trees will be failing soon. While October is generally considered a better tree planting month than November for us, temperatures are still warm enough to provide quite a bit of new root growth.
Once the investment of a new tree is made, it is critical to follow a few steps to help insure its long term success. These are not difficult tasks, but based on hundreds of observations, they appear to be often neglected. For the purposes of this discussion, we will begin with the assumption that the tree has been properly planted and its water needs are being met. If you have yet to plant this fall, contact the Extension office for advice on proper procedures.
Proper mulching is critical. In addition to serving the important role of moisture management, mulch also helps to limit competition with turfgrass. In our area, bermudagrass is an especially vigorous competitor for water and nutrients and keeping it away from a small tree will pay big dividends over the first few years of the tree’s life.
Always remember to avoid piling mulch up directly against the trunk of the tree. “Volcano mulching”, an industry term for poorly installed mulch piled around the trunk, acts as a harbor for disease and insects. At the trunk-soil interface, only a small amount of mulch should be used. The depth of mulch can then be increased to 2-3 inches once you get away from the trunk. The mulched area should, at a minimum, extend a bit beyond the original diameter of the root ball.
Proper staking is also important. In a nutshell, allow the tree some movement and make sure the stems/trunk is not damaged by the staking material. Except in extreme cases, one year should be plenty of time to leave staking materials on a new planting.
Your tree may have come from a nursery with a protective wrap installed around the trunk. This serves to protect the tree during the shipping and handling process. This wrap can also protect trees from one of the most common environmental stresses many species face; winter injury, also called southwest injury, or sunscald.
Winter injury is characterized by large sections bark splitting away from the trunk. This will almost always be on the southwest side of the tree. It is caused on cold but sunny winter days when the trunk warms quickly with the low winter sun. The bark wrap serves to prevent this overheating. My casual observations tell me that at least half of the maples planted in our area are damaged by this malady so it is an important factor that should not be overlooked.
Problems develop when this product is left on the trunk throughout the growing season. Just like with excessive mulch, wrap can harbor insects and disease. To prevent problems, remove trunk wrap each April and replace it again each fall (after leaf drop) until the bark begins to develop some signs of maturity.
Finally, emphasize the importance to everyone who might be doing lawn maintenance on the property the importance of protecting/not damaging the tree trunk with a weed trimmer or mower. Damage from these tools cannot be repaired.
For more information on this or any other horticultural topic, you can contact Keith Reed, the Horticulturist in the Payne County Extension office. Keith can be reached via email at firstname.lastname@example.org, phone at 405-747-8320, or in person at the Payne County Extension office, located at 315 W. 6th in Stillwater.
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