Forget the lawn — your trees need water to survive drought and scorching heat

Experts with USU’s Forestry Extension say your lawn will come back next year, but under-watered trees could die without proper care.

(Briana Scroggins | Special to The Tribune) Weber Basin’s Water Conservation Learning Garden in Layton offers ideas for trees that require less water.

With statewide water restrictions and scorching temperatures, homeowner across Utah may be worried about their lawn.

But Darren McAvoy and Mike Kuhns — forestry experts with Utah State University Extension — say we should really be focusing our limited water resources on the trees in our yard.

“A brown lawn will come back easily if water is available next year,” they wrote in a news release, “but an under-watered tree may die and it will take decades for another tree to replace it.”

They offered these tips to help trees survive the drought and sweltering heat.

• Trees and shrubs have deeper, more extensive root systems than grass, and should be watered slowly and for longer periods of time. To save water — and still have healthy trees — water every few weeks — but make sure you get to it before leaf wilting, scorching and other stress occurs.

• The soil needs to remain moist 18-20 inches deep around your tree. You can determine the moisture level by pushing a long screwdriver or metal rod into the dirt. It will easily penetrate moist soil but will stop when it hits dry soil. Don’t forget that the roots extend outward, too. Water an area that is about two-thirds the height of the tree.

• Are the automatic sprinklers providing enough water? Test the system by catching water in cans scattered around the irrigated area for a set amount of time. Small sprinkler heads that send a mist out can put out more water than you would expect, but if you don’t irrigate long enough, you may not provide enough water to get past the grass roots.

• Watering by hand with a hose can work well — as long as it is applied slowly enough to be absorbed by the soil. Consider placing a soaker hose or sprinkler turned on low over the tree roots during the coolest part of the day for two-hour intervals every few weeks.

• The amount of water needed for a tree depends on the weather and the tree’s drought tolerance. About one-half to 1 inch of water may be required weekly for shrubs and smaller trees. Large trees may require more.

• For newly planted trees and shrubs, water frequently until the root system is established.

• It is difficult to water trees adequately with a drip irrigation system because trees may need greater amounts of water than the low flow systems put out.

• Add mulch and control weeds and grasses around the trunk to reduce evaporation and competition for water.

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