Gardening: Cold may help kill off pests, but also plants
It’s been a long time since we had a good hard winter. We haven’t been this cold since 2010, and its barely past the solstice and the formal start of winter. Who knows what January and February will bring. We were spoiled during last winter’s unusually warm weather that let us garden almost through the entire winter. While the idea of plowing snow for three months isn’t very appealing, the extra cold weather and deep snow might be just what our gardens need.
Over the past couple of years, the WSU Master Gardener Plant Clinic has seen a steady rise in bug infestations and even the appearance of insects we haven’t seen here before. A long cold winter might just kill off many overwintering insect adults and larvae reducing the potential of damage to our vegetables, lawns and trees next summer.
Subzero weather might create another surprise for us in the spring: a lot of dead plants. Over the last few years many gardeners, myself included, have been emboldened to play the zonal denial game and plant exotics that are a zone or two above our average USDA zone five to six. We got away with it because our winter temperatures have rarely been below 15 degrees. Not so this year. The saving grace for now is that we have snow on the ground and only one week of really cold weather behind us. If we get some more subzero weather, we might be buying a lot of new plants in the spring.
If we get a break in the weather, there is still time to mulch plants with a thick layer of straw. You can find bales of wheat straw at most feed stores for around $8. Don’t use hay because it still has a lot of grass seed in it. Just break up the flakes of straw and lay it right over the snow. The snow is merely extra insulation for now.
Heavy snow also means an increase in broken branches on trees and shrubs. Stage some long poles so they are easy to grab and then gently knock the snow off the limbs before they break. Be aware that the branches are stiff and frozen and can easily be broken if you tap them too hard. Remember to wear a hooded jacket unless you like snow down your neck.
If you keep houseplants near windows during the winter, think about pulling them back a foot or so if we get subzero weather. Most houseplants are tropicals that are easily damaged by temperatures close to freezing.
After you’ve finished all these chores, there is going to be lots of time to settle in with the seed catalogs and planning the garden. I have received a few already and the pages are already covered with sticky notes about what I want to order. I will have access to some greenhouse space this year so I think I will experiment with some heirloom vegetables I can’t find as plants.
Pat Munts is co-author, with Susan Mulvihill, of the “Northwest Gardener’s Handbook.” Munts can be reached at pat@inlandnw gardening.com.