Quoting from an article I wrote in May, “This is shaping up to be a rough water year. In the coming months we are likely to see limited water supply and you should start now conditioning your lawn to put down deep roots.”
Unfortunately, that statement has proven to be true in the worst way. Our water supply is tight and getting more limited every day. Agricultural water delivery is closing off much earlier than in years past. All year long farmers have had to make tough decisions on how to manage their operations to get the most out of a short water supply. Whether you irrigate your yard and garden with secondary water, or rely entirely on water delivered through a municipal drinking water system, we all need to exercise restraint. We simply cannot use water the same as we are used to in more favorable water years.
If/when you are faced with the need to choose where to cut water, here is some guidance that will minimize the long-term negative consequences of a water shortage.
1) Young Trees/Shrubs
Top water priority is required for young or newly transplanted trees that have a limited root system. Supplemental irrigation is needed for these trees even when drought conditions do not exist. Trees grown in environments where their root zone is restricted or compromised, such as those in sidewalk planters, near streets, and near construction sites should be treated the same.
2) Established Trees
Trees take a lot of money, resources, and years to replace; therefore, trees should receive the greatest water considerations during drought. A tree’s water absorbing roots are primarily located in the top 12 inches of the soil. During drought, Colorado State University recommends trees grown in sites without lawn irrigation have 10 gallons of water each week per inch of trunk diameter measured. The trunk diameter measurement should be taken at 12 inches above the soil. For example, a 2-inch diameter tree requires 20 gallons of water per week. Water established trees at least two times per month while drought conditions persist.
3) Vegetable Garden
Vegetable plants will not produce without adequate water. Vegetables cannot revert to dormancy to avoid drought stress; therefore, it is important to provide adequate water if you hope for a harvest.
Don’t stress if you must let some of your lawn go during the next few months. Our cool season lawn grasses can go dormant while it is hot and regrow once moisture and cooler temperatures prevail. Don’t entirely stop watering, however. Utah State University recommends maintaining a minimum of 1-inch of water per month to keep the grass crowns from dying.