Trees and Shrub Watering Guidelines

 

According to the drought monitor, all of the counties of the Southwind Extension District are in a moderate drought. Unfortunately, in looking at the drought forecast, it doesn’t look like we will be out of this pattern anytime soon either. If you haven’t been supplemental watering trees and shrubs, you need to be – especially any that were newly planted this spring.

Newly planted or young trees and shrubs often don’t survive the first year because of improper watering. Proper watering throughout the first growing season often means the difference between success and failure.

Water should be retained around the base of the newly planted trees by building a low berm just outside the planting hole. A weekly soaking to apply approximately 10 gallons of water should be sufficient to support spring or summer planted trees and shrubs on most sites.  Larger balled and burlaped or spade-dug trees will require more water. For every inch of trunk diameter greater than two inches, an additional ten gallon should be applied. In the absence of rainfall, continue watering newly planted deciduous trees and shrubs until their leaves fall. Evergreens should be watered until the soil freezes.

It is easy to overwater and keep the soil excessively wet and cause a different set of problems. Over watering can cause “wet wilt” which looks similar to wilt caused by dryness. When soil stays wet for an extended time, root damage can occur due to oxygen depletion. As a result, leaves wilt and do not recover, even if water is added.

During the second and third growing seasons after planting, supplemental water every 10 to 14 days if it doesn’t rain and soil moisture indicates a need. Check moisture with a trowel, rod, screwdriver or probe.

With established trees and shrubs, supplemental watering should be done during periods of drought. Trees that have been planted for three to five years will benefit from deep, regular watering.  But the interval can be extended to two to three weeks between applications.

Check the soil moisture and use it as a guide. Soak the soil to a minimum depth of 12 inches, out to and beyond the drip line, every three to four weeks if it doesn’t rain significantly. Avoid watering established trees at the base of the trunk because the absorbing roots are further out. Shrubs should also be watered so the soil is moistened to a depth of 8 to 12 inches every couple of weeks.

Water can be applied through a soaker hose or by allowing a pencil thin stream of water from a garden hose to soak the ground. Water lances or “root feeders” are not as suitable as applying to the surface because they can actually introduce the water deeper than where the surface feeding roots are located.

If you have trees or shrubs that are not looking good, give me a call and a home visit can be scheduled to evaluate the problem.

Krista Harding is a K-State Research and Extension Horticulture agent assigned to Southwind District and may be reached at kharding@ksu.edu or 620-244-3826.

 

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