The ever-increasing number of tender plants on offer may not withstand sustained cold without some form of protection. How you protect your plants from the effects of cold depends on the type of plants and the situation they are growing in.
Plants that are trained against walls or tender plants growing in the open ground can be protected with simple, fleece-covered frames. Alternatively, sandwich a layer of bracken leaves or straw between two large sections of chicken wire and use this to cover plants during frosty evenings. Tender bulbs, corms and tender, herbaceous plants (that die back) should be covered with a thick mulch of manure, straw or old leaves to prevent the soil from freezing. In the spring, new shoots can be protected with a loose layer of straw or a bell-cloche.
Evergreen plants will benefit from a thick layer of mulch around their bases to keep the soil frost-free. This will allow them to take up moisture during periods of cold weather and stop them from becoming dehydrated.
Tender plants should be grown in pots so that they can be moved inside during bad weather. Take cuttings of those that cannot be grown in pots and overwinter these in a warm greenhouse, ready for planting in spring.
Protect the crowns of tree ferns and insulate their trunks by wrapping them in layers of fleece or hessian stuffed with straw. Cordylines and palms should be treated similarly, by tying their leaves into bunches, to protect their crowns.