Winters in the northwest can be unpredictable. As I look around my neighborhood, I can still see trees (like my neighbor’s corkscrew willow) that are green as grass and completely foliated, while next to them are maples that are fully denuded of all their summer leaves. My hostas have mushed down to nothing, but the roses are still blooming. Such is the nature of our Pacific Northwest falls/winters. You just never know when that hard “killing frost” is going to hit, but if you are not ready to deal with it, then you very well might suffer some serious losses. Here are some tips to manage the freezing events that will be coming our way…
1. First of all, if it is below freezing in the yard, stay out of it until things thaw out — this is especially true with lawns. Just remember to “keep off the grass” whenever it looks frosty or you will be leaving dead footprints everywhere you step.
2. Protect container plantings. While a Japanese barberry may be hardy to minus 40 degrees in the ground, it can freeze “deader than a doornail” in a container where the whole soil mass can freeze and kill the roots. I think that for the most part containers are fine down to the low 20’s, especially if during the day the mercury returns to above freezing. If you want to err on the safe side, consider wrapping your containers with burlap or blankets and/or move the pots closer to the house or a protected area. Just remember to remove everything once it warms up again. Never use plastic over the top of plants as it can heat up if the sun comes out and it will cook them.
3. In our mild climate, vegetable gardens will continue to produce as long as we keep the hard frosts away. I have a marvelous late season crop of broccoli, lettuce, and spinach that is looking good that I don’t want to lose, so I have already set in place some row cover that I can pull up and over them when I know it is going to freeze. Sometimes as little as a 5 degree increase can make all the difference in the world.
4. Hold off on any hard pruning. Severe pruning should be left until after the hard freezes are over, which for us is usually February. Selective or what I like to call light pruning can be done at almost any time of the year, as long as it is above freezing.
5. Watering. Yes, plants can sometimes need extra water in our winters, especially beds and containers that are under the eaves and don’t receive any rainfall. If we go a week or two without rain, then consider splashing some water around the yard to moisten the foliage of evergreens such as rhodies and conifers.
6. Mulch. Organic materials such as bark, compost, wood chips, or even fresh leaves, when spread over the bare ground an inch or two thick, work wonders to protect against freezes - not to mention the soil building benefits and weed suppression they provide. Just remember not to bank them up high against trunks and crowns of plants. Your goal is to protect the roots, not the stems.
Fortunately, since I moved to the northwest over 30 years ago, our winters have become increasingly milder (USDA has actually changed our zone from 7b to 8b) and even when we do have an “artic blast”, it rarely lasts more than 7 to 10 days. Consider taking some of the above steps and your garden will be that much happier come spring. Stay safe and keep on gardening!
Steve Smith is the owner of Sunnyside Nursery in Marysville and can be reached at email@example.com.