Winter container gardening can be tough on plants – they need protection from all the elements that winter throws at us – wind, frost, morning sun, waterlogging and drying out. Probably the most challenging aspect is protecting the roots from freezing in the pot. Plants are always better off in the ground during freezing winter weather, but if you can’t bury your pots (or don’t feel the inclination) you need to provide some extra protection.
Pots are expensive, so make sure that your container is strong enough to make it through the winter. The more porous it is, the more likely it will crack. It is worth investing in frost-proof terracotta and glazed pots which are more likely to withstand freezing temperatures. However, you will still need to protect the plant’s roots.
Don’t let the compost get waterlogged – keep it well drained. Place the pot under the rain shadow of a wall and group containers together by moving them to a sheltered position – close to the house is the best place. Raise the container up off the ground to keep the bottom of the pot out of the water – pot feet are ideal. If you let the pot stand in a saucer or on the ground, water cannot escape and will freeze in the bottom of the pot turning the roots to mush when they thaw out.
Wrap the container in bubble wrap leaving the base clear and put some horticultural fleece around the plant. Protect the crowns and trunks of tree ferns by wrapping them in layers of fleece or hessian stuffed with straw.
Spring bulbs can be protected in a similar way although they need more care than bulbs planted in the ground. You will need to keep the compost moist and protected from frost. You can protect them by moving the pots close to the house wall, covering the pot with a thick layer of straw or use a cloche or ‘hoop house’ and cover with horticultural fleece. Remove it when the weather improves. If you suffer from squirrels and mice eating your bulbs, protect them with a piece of chicken wire and remove when shoots appear.
All of this will certainly help to protect your containers and your plants throughout the cold and wet winter months.