Trees and Drought

This can be a problem in the winter as well as the summer.

Whenever there is insufficient rainfall, trees will need an extra 1 - 3 inches of water per week. To get that much water down without wasting it as runoff, split your applications. One to two deep or heavy waterings are much better than many shallow or light waterings.

During drought periods, trees need extra water to keep them growing vigorously. Without this extra water, tree roots die and you begin to get a general tree decline. Once weakened, trees are susceptible to damage from many pest—diseases and insects.

How do you get the water where the tree can use it without wasting it?

Recommended methods involve the use of drip irrigation or a soaker hose. Both methods allow for efficient water usage and they also limit the wetting of trunks and foliage. Overhead sprinklers are less effective and they promote pest problems by constantly wetting the foliage.

Locate your hoses at or close to the drip-line of the tree. The drip-line is an imaginary line that can be drawn out at the farthest extension of the branches. To conserve moisture between watering, keep a 2" - 4" layer of mulch over the root system. Good mulching materials are pine straw, wheat straw, pine bark, wood chips, etc.

Timing…

Timing your watering is very important. Local watering bans may dictate when. The ideal time to apply moisture is between the hours of 10 pm and 8 am. Trees pick up more water during those hours, there is less evaporation, and you can minimize the pest potential by not extending the normal dew period.

Winter droughts are as stressful as summer dry periods.

Whenever there is insufficient rainfall, trees will need an extra 1 - 3 inches of water per week. To get that much water down without wasting it as runoff, split your applications. One to two deep or heavy waterings are much better than many shallow or light waterings. Shallow watering encourages shallow roots, which in turn makes the trees even more prone to drought stress.

Prioritize your watering.

Turf grasses and most ornamentals are replaceable but 100 year old oak trees are not.

• The first things you should water are your newly transplanted trees, those put in this spring
• Next, water those trees that have only been in the ground for 2 to 5 years. These two groups have smaller, less established root systems and they would be the first ones to receive drought damage.
• Then carefully water all your specimen trees, those that have historical or social significance. Finally, water all the other trees

For more information on trees and drought, contact your local County Extension Office.