By: Jean Ferdinandsen, Certified Arborist
Water is the most limiting factor for good tree growth. Proper watering is the most important tree care step you can take. Without enough water, trees will not become well established after transplanting. Even established trees will become stressed, lose vigor, decline, and be more prone to certain insects and diseases. Water also can impact the effectiveness of various tree treatments from fertilization to insect and disease control.
If nature does not supply enough water on a regular basis, which has been the case the last two years, you need to provide supplemental water to your trees. Generally, 1" of rainfall per week during the growing season is considered adequate. Always check the soil to see whether it is moist or has dried out and is in need of additional water. Soils differ in their water holding capacity and how fast they dry out. Too much water will actually cause the roots to die off from lack of oxygen.
It is much better if you give a periodic thorough soil soaking, rather than a daily light sprinkling. Actually a light sprinkling can prove harmful. It is better to moisten the soil deeply, aiding roots in their normal growth, rather than water in such a way as to produce new rootlets in the upper soil surface where they are more drought susceptible.
Estimate and monitor the amount of water applied. It is desirable to have the water penetrate 6" to 8". Check the soil to see if this actually occurs. If using a sprinkler, place a pan in the area being watered and see how much is being applied and how long it takes. Soil soakers, porous hose, or using a slow trickle may also work well with less evaporative loss. Whatever method you choose, make sure the water is distributed evenly throughout the root zone.
Avoid watering during the heat of the day or when windy. With higher temperatures or winds, evaporative loss is high and only a portion of the water being applied benefits the trees. It is best to water in the cool of the morning or evening. Generally, apply water only to the soil and avoid wetting the foliage, as wet foliate is more prone to fungus diseases.
Different trees and soil vary in their water requirements. Try to be in tune with your trees’ needs and take a regular walk through your landscape to observe what’s going on. Continue to water as needed up until the ground freezes. This is especially important for evergreens.
As always, the Certified Arborists at Wachtel Tree Science & Service are available to help you with your tree care needs. Consult the experts in tree care to maintain your trees’ health and value.
© Copyright 2003 – Wachtel Tree Science & Service, Inc.