Supplemental Watering During a Drought
Written by: RJ Busch, ISA Certified Arborist WI-0985A
Posted: 2022 | Spring | Tree and Shrub Care
As we head into the growing season of 2022 there is one take away from the previous year, a drought. All four seasons saw below than average precipitation. Overall, we were roughly 13 inches below the normal amount of yearly precipitation. A drought like this can affect all trees, but younger and struggling trees are the most prone to water loss.
Proper watering will be even more important for your trees this season. If nature does not supply it, you will need to provide supplemental water. Roots need water to deliver essential moisture back above ground for the process of photosynthesis, which is necessary for plants to grow and survive. But it is important to understand that roots also need oxygen to survive and function. Oxygen is not available in waterlogged soil as it occupies the same pore space as water.
Most trees require one inch of water every 7-10 days, but one thing to remember is that the turf uses a large portion of water before the trees get a chance to soak it up. While the tendency is to think watering is basic, here are some tips to help you water properly.
First, always check the soil moisture before watering. To check the soil moisture, pull back the mulch and stick your finger in the soil approximately 1-2 inches deep to determine if the soil is dry. If the soil is moist, do not water. If the soil is dry, you will need to start supplemental watering.
Watering in the early in the morning or in the evening recommended as this helps avoid water loss due to evaporation. It is better to water deeply and less often as this promotes a deeper root system than frequent light waterings. To do this, you will need to wet to a 6-inch depth and repeat only when dry. Do not saturate near the base of trees as roots spread out two or three times the crown width. However, newly planted trees will only need water within the trees crown because they have not had time to develop an expansive root system. You will need to avoid wetting the foliage, especially on spruces, pines and crabapples, to help prevent fungal foliage diseases. Evergreens should be watered up until the time the ground freezes to help defend against winter desiccation and damage.
What else can you do? Retain available soil moisture by the proper use of mulch. I like to recommend removing the turf underneath the trees drip line. Adding a 1inch layer of compost followed by a 2–3-inch layer of any organic mulch. Rebuild the tree’s root system and uptake abilities with mycorrhizae, root biostimulant treatments, and compost tea applications. Some of these treatments also build a healthier soil and reduce disease potential.
The Certified Arborists at Wachtel Tree Science can help assess the condition of your trees and the effects of this long-term water deficit. We will recommend the best course of action for you and your trees, so give us a call today to keep your trees healthy and beautiful.