British winters are nothing if not unpredictable. One week you're enjoying gentle drizzle and a mild ten degrees, the next you're scraping ice off the car and watching your prized olive tree turn an alarming shade of grey. Frost doesn't just nip at tender bedding plants; it can split pots, blacken foliage and see off roots that took years to establish. The good news is that a little preparation in late autumn goes a very long way. Here's how to give your plants the best possible chance right through to spring.

Start with the Pots: Move and Wrap

Container plants are always the first casualties. Their roots sit above ground in a relatively small volume of compost, so they freeze far faster than anything planted in the border. Before the first hard frost is forecast, move every pot you can into a sheltered spot. A south-facing wall, a porch, an unheated greenhouse or even the corner beside the house all offer a few precious degrees of protection. Cluster pots together rather than spacing them out; grouped containers insulate one another and cut down on wind exposure.

For pots that are too heavy or too well-established to move, wrap the container itself. Bubble wrap is the traditional standby and works beautifully. Wrap it around the pot, bubble side facing inwards, and secure it with twine or tape. Remember that it's the rootball you're protecting, not the foliage, so cover the sides down to the base and, if you can, stand the pot on wooden blocks or pot feet to keep it clear of freezing paving. Terracotta and glazed pots are particularly vulnerable to cracking when wet compost expands as it freezes, so wrapping also saves the pot itself. Raise pots onto feet anyway so winter rain drains freely rather than sitting in the saucer.

Fleece: The Gardener's Winter Blanket

Horticultural fleece is one of the most useful things you can keep in the shed. It's lightweight, lets light and air through, and can lift the temperature around a plant by a couple of degrees, which is often the difference between survival and a mushy mess.

• Drape it loosely over tender shrubs, tree ferns and newly planted evergreens, then peg or weight the edges down so it doesn't blow away.
• Double up two layers for borderline-hardy plants, but keep the fleece off the foliage where possible by using a frame of canes or a cloche.
• Use fleece jackets or wrap the trunks of young trees and palms with fleece secured with soft ties rather than wire, which can cut into bark.
• Lift it on mild days to let air circulate and prevent mould, then tuck everything back in if frost returns.

Fleece is best put on before the cold arrives, ideally during a dry, mild afternoon. Don't wait for the first frost warning; by then the damage to soft growth may already be done.

Mulch Deeply to Protect the Roots

In the open ground, the soil itself is your greatest ally. Deep, dry mulch acts as a duvet over the root zone, slowing the rate at which the ground freezes and, just as importantly, stopping it thawing too quickly when the sun comes up. That repeated freeze-thaw cycle is what heaves plants out of the ground and snaps shallow roots.

Spread a generous layer, roughly five to eight centimetres deep, of well-rotted manure, leafmould, bark chippings or garden compost around the base of shrubs, perennials and fruit bushes. Keep the mulch clear of stems and trunks, leaving a small gap so damp material doesn't rot the bark. Evergreen shrubs, Japanese maples, hebes and young fruit trees respond especially well to this treatment. If the ground is already frozen, don't mulch over it; wait for a thaw, as mulch on frozen soil traps the cold in rather than keeping it out.

Think About Water, Wind and Timing

Frost damage isn't only about temperature. A plant that's bone dry going into a cold snap suffers far more than one that's been watered sensibly through autumn. Water evergreens and newly planted shrubs during mild spells in winter, but never water when the ground is frozen or a frost is imminent. Wet foliage freezes fast, so keep the water at the roots.

Wind is the other silent enemy. Cold, drying winds strip moisture from leaves faster than roots can replace it, which is why so many evergreens emerge from winter with scorched brown foliage. A simple windbreak of fleece, netting or even a few woven hurdles placed on the prevailing windward side will make a remarkable difference. Avoid plastic sheeting, which traps condensation and can cook plants on a sunny January day.

Timing matters too. Feed plants in late summer rather than autumn, as soft, sappy growth produced by late feeding is the first thing to be damaged. Stop deadheading and pruning tender plants by early autumn so growth has time to harden off before the cold arrives.

Quick Daily Habits That Save Plants

• Check the forecast each evening and act before dusk, not the following morning.
• Cover tender seedlings with a cloche, an old fleece or even a flowerpot for the night, and remove it the next day.
• Brush snow off evergreens, conifers and greenhouse roofs before its weight snaps branches.
• Avoid walking on frosted lawns, as the blades break and blacken where feet crush them.
• Keep the bird bath thawed and top up feeders; garden birds repay you by clearing overwintering pests.

Do these jobs well and you'll lose far less to the cold. Come March, when the soil is workable again, your garden will already be a few steps ahead, ready to grow rather than recover.