Stress from drought can seriously impact trees and shrubs. Leaves will wilt and drop. Overall tree growth is reduced and trees are more likely to become infested by insect pests or disease. Ultimately, if the water lost from leaves or needles is not replenished, the plant will dry out and may die. Here are some recommendations to help prevent moisture stress and loss of plants when drought hits.
Proper Irrigation During Dry Weather
The tree and shrub roots most responsible for water uptake are typically in the top six inches of the soil. Some trees are more adapted to drought, however, and grow deeper roots. With this in mind, irrigation will depend on the species as well as current weather conditions.
During the growing season, irrigate shrubs and shallow-rooted species once a week. Be sure to run the hose or irrigation system long enough to moisten the soil to a depth of six inches or more. For more drought-adapted species, you may only need to irrigate every two to four weeks. Do not water daily or every few days. This may be good for turf, but is likely to cause problems for tree and shrub roots. Over watering can be as bad as too little water so be careful to irrigate landscape plants correctly.
Mulch to Conserve Soil Moisture
A two- to four-inch layer of organic mulch on the soil surface helps conserve soil moisture. This is one of the lowest-cost, most effective ways to reduce drought injury. Over time, organic mulch adds organic matter to the soil, promoting root development and improving the soil’s moisture-holding capacity. Mulched areas eliminate competition for water and nutrients from turf or other ground covers. Use any organic mulch (wood chips, shredded bark, bark nuggets, pine straw, leaves). Apply mulch any time of the year using these mulch application guidelines.
Determine Soil Nutrient Needs
A soil test before fertilization can identify which nutrients are either lacking or in excess. If potassium is deficient, fertilization with this element is especially important to aid plants in overcoming drought damage. Certain forms of potassium fertilizers can also increase plant defenses to several common diseases. We can collect soil samples and apply slow-release fertilizer at any time when the soil is not frozen or too hard due to drought conditions.
Manage Insects and Disease
Plant diseases and insect pests weaken trees by damaging leaves, branches, stems, or roots. This damage makes it hard for trees to absorb and move water and nutrients, worsening the effects of drought. Identify pest and disease issues early, before serious problems develop. A Certified Arborist can check for pests and disease and apply treatments at the right time.
Over time, drought has become more common. Whether it is persistent or occasional, drought affects many tree and shrub species. It is best to take precautionary actions to lessen the effects of drought, thus reducing damage to your landscape. When replacing or adding plants to your landscape, be sure to check to see if the species are drought tolerant for your geography.