Tips for caring for tree’s and shrubs in a drought
Check your irrigation system
Check your system’s coverage by placing out straight-sided cans at several locations, and measuring the depth of the water. Replace damaged heads, and adjust heads to avoid watering streets or driveways. Water between 9 PM and 6 AM. If you do not have an automatic sprinkler system, use a bubbler at the end of a hose to apply water at a low rate at several locations away from the main stem.
_ Irrigating trees and shrubs during a drought
Soak the root system once every 4-6 weeks, which will increase the plant’s drought tolerance. Water the entire root zone. Apply water at a rate that allows maximum infiltration at the rootzone, but limits runoff. Remember that the roots of established trees are three to five times the height of the tree and that the roots of shrubs also extend wider than the above-ground plant.
_Long-term planning for a water-efficient landscape. Select trees and shrubs for the landscape that are tolerant of low water situations. Instead of planting spruce, plant pines; pines require less water. Trees and shrubs have varying degrees of water requirements. Place those with the same water needs together and irrigate to their requirement. Use drought-tolerant materials and xeriscaping practices for long-term water conservation.
_ Fertilize sparingly Do not apply nitrogen fertilizer just prior to the heat of mid-summer; severe stress can result requiring more frequent applications of water.
_ Mulch Kill turf near trunks of trees and shrubs with a herbicide such as glyphosate. After the grass has dried, apply a layer of mulch. Mulch the area around trees and shrubs out as far as possible with an organic mulch layer. Apply a layer of mulch two to four inches deep around trees and shrubs to increase their health; healthy trees are more tolerant of drought stress. Keep mulch a couple inches away from the trunk tissue. Use organic mulch such as bark or wood chips; avoid the use of stone or rock as mulch near plants as this increases air temperatures and moisture loss from leaves and stems. Be sure your mulch layer is in place.
Consider delaying new plantings
New plantings require more water than established plantings.
Michael Bauer is the Extension Horticulture Agent for Colorado State University in Eagle County. Mike works with green industry and coordinates the Master Gardener Program, in which trained volunteers provide gardening information to local residents.
Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. Cooperative Extension programs are available to all without discrimination. If you would like more information, contact the CSU Eagle County Cooperative Extension office at 328-8630.