How to Grow Clematis in Containers in the Frozen North P.4

4. Wintering Container Clematis

Wintering clematis in containers in the Frozen North takes a little extra effort but not because of cold winter temperatures. Instead, problems can arise when things warm up and the snow on the top of your container melts. All that snow becomes ice water and saturates the soil, leading to root rots. Nothing makes a fungus happier than really wet, really cold conditions!

You can prevent this in two different ways. First, you can move the container into a dark, cold place for the winter. We move most of our containers into the greenhouse in the fall and leave them there until early spring. The second option is to cover the container with a sturdy, waterproof material like plastic or bubble wrap so that the water can't get into the container. Don't use tarps, as water can drip through them and soak the soil. Ask me how I know....

Will your container stand freezing winter temperatures? If not, follow the first option and move it to a place where it will not freeze.

If you choose to cover your container and leave it outside, the question then is "To Mulch or Not to Mulch"? Your plant is healthy and in a freeze-safe container 24 inches or more in diameter? Don't bother to mulch, unless it will make you feel better. If the plant is in shaky condition or the container is less than 24 inches across, mulch away. You can mulch the soil surface, but the really important thing is to mulch around the outside of the container. Bagged leaves work well here. Important note: do NOT mulch until after the soil in the container has frozen. It's not being frozen that does the damage to the plant - it's freeze-thaw-freeze cycles. So let it freeze - then keep it frozen!

Back