Trees are greatly beneficial to our home landscapes. They provide shade, provide habitat for wildlife, help retain soils, and add visual interest. It is important that we take care of our trees. Many things we do for our other plants in the landscape may provide benefits to our trees at the same time, such as watering, fertilizing, and aerating. However, some maintenance practices may unintentionally damage our trees.
Improper mulching often does more harm than good. Whenever possible, manage your mulched areas so they extend to the edge of the drip line of your trees. This is the area around the trees where the watersheds from the canopy.
Mulch applied too thickly can create many problems. A layer 1-3 inches thick, depending on the mulch type, should be adequate in most situations. Building a ‘bird’s nest’ of mulch 12 inches deep and 12 inches wide around each tree does not provide much benefit. Mulch piled against the trunk is one of the most frequent “tree-killing” practices I see on a weekly basis. Mulch touching the trunk can cause rot issues, and can even cause the death of your tree’s root system. Pull your mulch back 3-5 inches from young trees and 8-10 inches from mature trunks.
Weed control can also help your trees. Hand-pull any weeds that come up near the trunk. Using a string trimmer or mower close to the trunk can injure to the bark and underlying cambium layers. Using a post-emergent herbicide around root zones may also damage trees. High concentrations of certain herbicides, like 2,4-D, during warm spring weather, may be taken up by tree roots and result in distorted leaves. Most pre-emergent herbicides won’t harm trees. Always read the label, as herbicides that may cause tree damage have warning statements on the label. Avoid spraying on windy days and set your wand for large droplets to reduce drift.
Stakes and guy wires are often used to hold up young trees until they become established. Many times, the wires are forgotten and as the tree grows, they become embedded in the bark and cambium layers. This can severely girdle the trunk, often resulting in gradual tree death. Remove plant tags and trunk wrap from the nursery to prevent tree injury in the future.
Tall trees are often seen as a hazard. Many people mistakenly believe that topping trees is a good way to reduce the size of a tree. Topping is not a viable method of height reduction, and it does not reduce the hazard. It actually makes trees more hazardous in the long term and doesn’t promote a healthy tree.
Installing irrigation systems and rototilling planting beds are common ways that root systems are damaged. Also, adding as little as 2 inches of extra soil on top of existing root zones can be devastating to your trees. Avoid the temptation of adding more soil around root systems that have begun to stick out of the soil surface.
During periods of drought, homeowners often water lawns and neglect trees. In situations where turf and trees are growing together, watering lawns can be beneficial to trees if done correctly. Frequent, shallow watering doesn’t meet the needs of either turf or trees and can be harmful to both. Both need the equivalent of 1 inch of water every 7-10 days.
Many people put a lot of hard work into their landscapes every week. Ensuring that maintenance practices aren’t harming trees is a good way to protect the valuable assets that are trees. To schedule an appointment for me to inspect your property’s tree health or any other questions on your home landscape, contact the Dawson County Extension service at (706) 265-2442.