Wind. Air in motion. On a hot summer day, a breeze is heavenly. But fierce, damaging winds over 50 to 60 miles per hour are another story. And, this has been a winter of winds.
In winter, high winds are caused by horizontal air pressure differences – masses of hot air and cold air. These large temperature contrasts result in a jet stream in the upper troposphere bringing strong whipping winds that blow over fences, tear off roof shingles and uproot mature trees.
It’s not just trees that suffer. Forceful, persistent winds dry out needle and branch tissues, causing damage. Wind contributes to soil erosion and root damage. During the Jan. 9 mega-wind – along with other damage – high winds blew away so much mulch and soil in one corner of my garden that allium bulbs were exposed. Sustained wind increases moisture loss from soil, and can leave moisture levels dangerously low
How to deal with the survivors:
Trees: First, assess the damage and be careful around large trees and power lines. Call an arborist if the tree is leaning or if there are major broken limbs high in the tree. Large, mature trees that are leaning probably cannot be saved. Sometimes young trees can be gently pulled upright. Again, this is a job for a professional.
The bad news: It will be harder for the tree to recover if there many large, broken limbs. And, if there are cracks in the trunk, or roots are exposed and lifted out of the soil, even if the tree is upright, chances for recovery are limited.
The good news: There are things you can do to help your trees that haven’t had as much damage. On branches closer to the ground, you can cut down broken jagged limbs or loosely hanging attached branches. Then remove branches that are cracked or broken. Do not remove or prune more than is necessary right away and don’t use paint or ‘wound dressings’ to cover the cut. After you remove broken branches you can leave fine pruning to early spring.
Roses and shrubs: Wind-whipped broken canes and branches can be cut back to just above the break.
If you have significant soil erosion on slopes, terraces and hills plan to create a defense to control erosion. Replace as much soil as necessary and plant hardy groundcovers and creeping shrubs such as Sedum Angelina in sunny spots and Sweet Woodruff in shade. Add some rocks or a boulder in strategic places. Cover any exposed soil until the groundcovers fill in with a one-and-a-half-inch layer of mulch.
Trees and shrubs have a remarkable ability to recover so once you’ve pruned back dangling, broken branches wait until spring. Don’t fertilize any tree or large shrub that’s recovering from this major stress. On warmer days, when temperatures are over 40 degrees, water trees, shrubbery and garden areas deeply where perennials are planted. If your mulch has been blown over the lawn rake as much as possible back into the garden and around trees.
Living in Colorado means always dealing with wind. Fortunately, the wild weather we experienced on Jan. 9 is rare. But preparing for wind in all its forms and knowing what to do when serious damage occurs in your landscape is smart.
For answers to urban horticultural questions, contact ask.extension.org. You can also follow the El Paso County Master Gardeners on www.facebook.com/ColoradoMasterGardeners.EPC/.