Gardeners have spent the summer watering their landscape trees in an effort to keep them alive and healthy through the drought and extreme heat. There’s no rest for the weary gardener even asthe temperatures begin to cool off. It’s important for tree health to prepare them for winter.

 

While some animals hibernate throughout the cold season, tree roots continue to grow during the winter and need moisture to survive. Roots can become damaged in dry, cold soils, so it’s important to keep them watered. Plus, moist soils hold more heat, which is great for the trees.

 

Trees produce two types of roots. The large perennial roots provide anchorage for the tree, water and mineral conduction, and food and water storage. These larger roots are woody and increase in size and grow horizontally. Did you know about 90% of a tree’s roots are in the top 12 inches of the soil?

 

Smaller, short-lived absorbing roots are about 1/16 inch in diameter and make up the major portion of the roots surface area. They’re responsible for the absorption of water and minerals. They grow upward from the perennial roots toward the surface where minerals, water and oxygen are abundant.

 

Knowing how tree roots grow helps determine the best method to water them. Water to at least a depth of 12 inches. Be sure to saturate the soil around the tree and expand out to the dripline to disperse water to those roots. Water slowly and deeply. Shallow watering encourages shallow rooting.

 

In addition to deep watering, here are a few more tree maintenance tips that can increase a tree’s chance of survival throughout the winter.

 

Mulch

Add 2 to 4 inches of organic mulch to reduce moisture loss. Wood chips, shredded bark, leaves or evergreen needles are good choices for organic mulch. Homeowners may prefer the look of grass under the trees, but mulch is better for the tree and more representative of the tree’s natural environment.

 

Fertilizer

Don’t fertilize trees that are under drought stress. Salts in fertilizer can burn roots when there isn’t sufficient water to disburse it. Fertilizers also can stimulate top growth, resulting in too much leaf area on the tree for the root system to maintain during periods of limited soil and moisture.

 

Pests/Disease/Overall health

If your trees have any insect or disease problems, treat accordingly to reduce the overall stress on the trees. Postpone any construction activities planned near the trees to reduce impact to the root system. Also, avoid foot traffic as much as possible to reduce soil compaction.

 

Pruning

Properly prune trees and shrubs during a drought to improve structure, limb stability, and to remove dead and weakened branches. Leaving dead, broken, insect-infested or diseased branches can further weaken a tree and set it up for deadly secondary insect and disease problems.

 

Lawn Herbicides

Some trees can be damaged by herbicides used on the lawn, especially those already drought stressed. If herbicides are necessary, it’s best to do only spot treatment if possible. Be sure to follow label directions.

 

These guidelines will help homeowners preserve their trees. Trees are an investment and add value to the property.