Here in Southern California the Santa Anas are upon us. These drying winds (hot or cold) that blow down through the mountain passes bring extremely low humidity with them. This combination of wind and low-to-no moisture can wreck havoc in your garden, especially if you’ve just put some new plants in the ground.
Dry winter winds can cause severe damage to plants and trees just as they can in the warmer months. Today it’s cold and the humidity is around 10% (I’ve got lip moisturizer in every pocket). That means I’ve got to get out into my garden and make sure that the plants are well watered.
If your area is having a dry winter, you should give your plants a good long drink before the ground freezes, or do it when the weather warms up enough that the water can soak down into the roots. You should also check to be sure you’ve got a good layer of mulch around the root zone. This will help your plants survive the winter by retaining ground moisture.
Young trees and shrubs planted recently (in the past 1 -2 years) can be damaged by drying winds and little snow fall in the colder climates. Besides providing sufficient water, you can create protective windbreaks by driving 3 – 4 stakes in the ground around your plant and wrapping burlap around the stakes, leaving the top open for rain or snow. Don’t use black plastic because it can heat up in warmer weather and encourage your plant to speed up new growth in the early spring leaving it vulnerable to frost damage when the weather turns cold again.
Evergreens can be particularly susceptible to desiccation (http://pubs.ext.vt.edu/426/426-500/426-500.pdf), which is when water is lost faster than the plant can take it up from the ground. Besides watering, mulching and providing windbreaks, you might want to consider spraying an anti-transpirant on the younger, more exposed evergreens. Wilt Pruf is a natural organic pine emulsion that does a good job of reducing moisture loss through the foliage of ornamentals such as azaleas, evergreens, rhododendrons, hollies, boxwood and laurels.
So briefly, no matter what climate you are in winterize your plants by: