Trees provide great benefits to our home landscapes. They provide shade, help retain soils and add visual interest. It is important that we take care of our trees.
Many of the 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 may do more harm than good for our trees. Whenever possible, try to let the mulch extend to the edge of the drip line. This is the area around the tree where the water sheds from the canopy.
Mulch applied too thickly can create many problems.
A layer 2-3 inches thick should be adequate in most situations. Building an "ant hill" of mulch 12 inches deep and 12 inches wide around each tree does not provide much benefit for the tree, When mulch is piled against the trunk it can create insect and fungus problems. 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. Small wounds can eventually turn into large holes which can let in fungal rot and insects.
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. Herbicides that may cause tree damage have warning statements on the label. Avoid spraying on windy days and use coarse 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 imbedded 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.
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 these valuable assets.