Bubblewrap container insulation
The cold November weather can cause problems for container plants, especially if they’re not in a frost-proof pot. When your plants are in the soil, their roots are protected by the warmth of the earth, but pots leave them exposed. Frost poses a threat to not just the plants but also the containers themselves. In some cases, you could try to move your plants inside for the duration of the cold spell or even the entire winter, but that’s not always possible. That means it’s important to take some precautions and protect them as best you can when the temperatures drop.
A lot of the issues caused by cold and frost in the winter comes from water. Wet compost can freeze during icy weather, which kills the roots of your plants. Not only does the waterlogged compost kill the roots when it freezes, but it can also crack or even break the plant pots. Water expands when it freezes, which causes it to break out of its container. Terracotta is particularly vulnerable to this type of damage, so it’s crucial that non-frost-proof pots are protected with insulation.
The tops of plants are usually pretty hardy to withstand the wintery conditions - it’s the roots that are at risk. Which means when you’re looking to add a protective covering, it should be around the pot or container. One simple and cost-effective material you can use is bubble wrap. Wrap a double layer of your wrap around the container and tie it in-place with some string. This should be enough to insulate against several degrees of frost. Just make sure you don’t cover the compost surface with your insulation, or your plants might rot. If you have a greenhouse, you can even use bubble wrap to create a double-glazed effect by pegging it to the inside of the panes.
Another way you can insulate your plant pots is with a plastic bag that’s filled with a layer of stuffing. Stand your container plant in a plastic bag - a black bin bag should do the job. Then fill it with anything you can find to create an insulating layer. It could be crumpled up newspaper pages, shredded paper or even straw. It’s a great way to give another purpose to materials that you’d typically just get rid of. Once you’ve padded out the plastic bag, tie the top loosely with some string or a plastic tie. Just make sure to prevent the plastic from touching the leaves; it can freeze to them and cause cell damage.
The reason that plants in the ground are better protected in winter than container plants is because the warmth from the soil keeps the roots protected. So if you have smaller container plants, you can take advantage of that natural insulation as opposed to wrapping your plant pot. Dig a hole that’s just big enough for the container to sit in, and just deep enough that the rim is still above ground. Then place it in there and cover it up. The warmer ground temperature will have you covered during colder spells.