The Met Office is circulating warnings of a beast of a winter, and where this may turn out to be as accurate as the barbeque summer that never was, it’s always good to prepare our gardens for the worst that the Arctic might throw our way.
In an average British winter, it would be unusual for temperatures to fall much below -5°C for any considerable length of time, particularly in milder areas like southern England. Chilly though this is, most garden plants will cope with these temperatures without the need for special protection. There are of course some plants that need to be wrapped up in fleece, packed with straw, or bundled into the greenhouse, but most plants will sit the winter out in a state of dormancy and perk up when conditions improve in spring.
However, there are a range of plants termed “half-hardy” which will struggle with more extreme conditions such as those experienced in 2018’s “Beast from the East”. Plants such as some hebes, salvias, pittosporums, fuchsias and many of the Mediterranean plants are included in this group and it’s worth taking some simple precautions to give these plants the best possible chance.
Actions to do now
- Lay a 5-10cm-thick layer of compost or bark chip over your borders. It will help retain the heat that the soil has built up over the summer months and act as an insulating layer for the roots. If you haven’t enough compost to cover your whole border, then just mulch around the plants which you feel most need protection.
- Don’t cut back your perennial plants. Instead, leave the stems and old foliage in place. This will provide the crown of the plant with a degree of protection from the weather. It may look messy, but by leaving the stems and old seed heads in place, you are also providing food for the birds and places for overwintering insects to shelter.
- Once the temperature drops, tender plants like cannas and dahlias should be chopped back and their tubes stored for winter (see previous blog, Wrapping up your plants for winter). The other alternative is to chop back plants such as dahlias, keep them in the ground and cover them with a super-thick layer of compost. This works for me, and my dahlias return year after year, though here are no guarantees…
- It also can be worth investing in horticultural fleece. This is sold in sheets of lightweight, semi-transparent material, which you can place over your shivering plants during a really cold snap. They need to be weighted down to stay in place, and don’t need to be removed until the cold snap has passed.
Most plants have mechanisms in place to deal with extra-cold conditions, particularly if they have already experienced a very cold winter, so it’s only a small number of plants that might be at risk. Either way, mulching and waiting until spring to cut back and clear up are both good gardening practise. So, if predictions of a cold winter turn out to be nothing but a load of “hot air”, then your efforts this autumn will not have been in vain.