Over the past few years we’ve seen effects in the landscape from an extended drought, specifically in the West. Meteorologists are, once again, predicting above-average temperatures and below-average precipitation for 2016 in the Willamette Valley. Signs of drought stress can easily be seen in the declining health of regional trees. Dead limbs in tree crowns, and brown, curling leaves are indicators of such stress. Oaks, ash, pines, and cedars, in particular, are rapidly declining in health throughout the Valley. While we certainly will not be able to save all of the trees, there are steps and procedures we can put into place to help extend the health and life of them.
During the summer months, trees should have watering priority over lawns. Lawns will more than likely rebound over the wet seasons, but a tree is to be thought about in a different manner. Due to changing climate patterns, it will take more care and water to keep trees thriving in the Western region.
An easy way to remember water needs for various trees is 10 gallons per inch of trunk diameter. The trunk diameter should be measured at about two feet from ground, and the general formula: tree diameter x 5 minutes= total watering time.
For example, using a hose at medium pressure usually takes about 5 minutes to obtain 10 gallons of water. Therefore, if you have a 5” diameter tree, it should receive 50 gallons of water; multiply by 5 minutes to equal total watering time of 25 minutes.
Water should be distributed evenly under the drip line of the tree, and not necessarily against the trunk. Also, trees should be watered three times per month during April- September.
DeSantis provides deep root watering, as well as deep foot fertilizer feedings, for our customers. Basically, a soil probe is injected approximately 8” into the soil, throughout 12 different areas within the drip line of the tree (less probing for smaller trees). This is a quick, efficient, and easy method to get water evenly distributed to the vast root system of trees. We have witnessed significant health advantages, and renewed growth in trees of customers who have opted to have the deep root watering and fertilizer feedings.
As we get further into the hot, dry summer months it is not recommended to add fertilizer to the injections, as this could burn trees that are already under stress. We do, however, recommend simple deep root watering during these months, and to apply fertilizer injections from October-March.
If you are seeing signs of stress, i.e., browning leaves or needles, dead limbs throughout tree branching, please consider adding deep root watering injections to your landscape trees. Contact your Account Manager today to arrange for deep root watering, as well as timely fertilizer injections. You will certainly see a noticeable difference in the health and performance of your trees.
Jamie Sloan, Account Manager