By Jennifer Lennox
For the Reporter
In 1890 Washington state was coined the Evergreen State. The nickname appropriately given as the forests were full of evergreen trees and the abundance of rain kept them green throughout the year.
These stately evergreens have grown accustomed to Washington’s rainy season and rely on the plentiful rainwater to thrive.
“Our unseasonable warmer weather is tricking some trees and shrubs into thinking it’s spring,” explains Rick Castro, district manager for The Davey Tree Expert Company. “And our recent lack of rain may cause problems for our evergreen forests and other plants in the coming years.”
Castro says the unseasonable weather makes trees more susceptible to disease, increasing the likelihood they will fall or break. There are several types of defects that can increase the risk of failure.
• Dead wood — Dead trees and large, dead branches can fall at any time.
• Cracks — Deep splits through the bark extend into the wood of the tree. Internal or external cavities.
• Decay — In advanced stages, soft wood or cavities where wood is missing can create hazardous conditions.
• Weak branch unions — Two or more branches grown too closely together, increases their chances of splitting.
• Root problems — Without a strong root system, trees are more likely to be uprooted or blown over in stormy weather. Look out for nearby construction that may sever large roots or compact the soil too much to allow for healthy root growth.
Castro says homeowners can help protect their trees during this mild winter by following a few steps. Watering, especially during a dry winter, prevents root damage. Roots continue to grow even when soil temperatures drop into the 30s.
“Affected plants may appear normal and resume growth in the spring,” Castro said. “However, weakened plants may die in late spring or summer when temperatures rise, and they are also subject to pests and diseases.”
Tree and Shrub Watering Basics
• Winter watering should be done from October through March.
• Water only when air temperatures are above 40 degrees F.
• Apply water at mid-day so it will have time to soak in before possible freezing at night.
• Monitor weather conditions and water during extended dry periods without snow cover—one to three times per month.
• As a general rule, apply 10-20 gallons of water for each diameter inch of the tree. Decrease amounts to account for precipitation.
•Trees obtain water best when water is allowed to soak into the soil slowly to a depth of 12 inches.
• Water directly to the most critical part of the root zone using sprinklers, an arborist’s tool called a deep-root fork or needle, soaker hose, or soft spray wand.
• Apply water to many areas under the dripline and beyond if possible.
• Add a layer of mulch to conserve soil moisture.
Following these watering guidelines will help ensure trees survive the winter and can continue being the most valuable asset in the landscape.
Finally, consult an arborist. Regular tree maintenance can make a world of difference. Not all tree risks are visible or obvious, advanced analysis, sometimes through the use of specialized tools or techniques, may be necessary. Arborists will evaluate the tree, soil conditions, wind exposure, defects, overall health and other factors to determine a tree’s hazard potential.
For more information on the Davey Tree Expert Company, visit their website.