Q.over wintering potted plants (perennials)
I have some plants in pots. Some of them are perennials. What is the best way to over winter them? I live in Bellingham, WA. Which is zone 7 or 8, I think. Thank you.
Certified GKH Gardening Expert
While it really depends on the type of plants as previously stated, you should treat plants in pots as though they need to survive one zone lower than your current zone. This is due to the fact that containers lack the insulation that plants in the ground have. You can combat this somewhat by placing the potted plants near foundations and mulching, but they are still going to be more susceptible to temperature fluctuations than plants in the ground. Therefore, if you have an attached garage or basement that you could store the containers in, this would be your best bet for getting them to make it through the winter. Another option would be to bring them inside. Those inside would require water once monthly to prevent complete drying out during dormancy. Once warmer weather returns in spring, the plants can be moved back outdoors and given additional watering and fertilizing.
It depends partially on what kinds of plants you have. Tropicals will need to be brought inside to a sunny area; perennials can be treated like a houseplant, or you can cut them back by about a1/3 and put them in a cool, dark spot to go into dormancy. Or the hardy perennials can be left outside; you can put the pots into holes in the ground to make sure the roots are protected from freeze. This article will tell you more about bringing plants indoors: https://www.gardeningknowhow.com/houseplants/hpgen/acclimate-plants-indoors-winter.htm
BTW, you can find your hardiness zone at this site: https://www.gardeningknowhow.com/planting-zones/usda-planting-zone-map.htm