Frost Damage

by Alan Titchmarsh

The coldest winter for 100 years – worse even than last years, which was ‘only’ the coldest for 30 years – predictably took us all by surprise. The snow and ice had an instant and all too obvious effect on airports, roads and water pipes, but for gardeners the worst is still to come.

As the start of the growing season unfolds, plants that you fully expect to burst into bud may drag their feet for weeks – or fail to do anything at all. So what’s the prognosis?
This winter is sure to have taken its toll on tender plants. If you didn’t get round to moving borderline hardy patio shrubs back into the conservatory for the winter I wouldn’t be too optimistic about their chances.

The same is almost certainly true of dahlia tubers that you may have left in the ground; if they survived the frost they probably rotted in the wet that followed – all you can do is wait and see. And if you didn’t heat your greenhouse or conservatory then it’s also likely that you’ve lost most of the pelargoniums, fuchsias, succulents and other tender plants you over-wintered out there.

You can easily tell; by now, frosted pelargoniums and succulents will look brown, soft and mouldy, and they’ve probably collapsed completely. If you’re lucky there may be a glimmer of life left at the base of the stem if the compost was very dry so cut them back hard to remove rotten tissue that acts as a source of infection, then wait and see.

Twiggier plants such as fuchsias go brown and brittle. Try breaking off the tip of a shoot; if the stem is still pliable and the inside looks creamy-green it’s probably still alive, but if it’s buff and snaps crisply then that part is dead – keep snapping further back until you find a live bit closer to the base that will eventually produce some new shoots.

Some slightly tender outdoor shrubs may not make it, but a few that look pretty dead right now are just faking it,. Phygelius, romneya and hardy fuchsias usually produce new shoots from below ground, so wait till May when new growth should start appearing at the base of the plants before pruning the dead old stems down to ground level – don’t do it earlier, since the plant needs them for protection. Ones to worry about are drought-tolerant Mediterranean and Californian plants, which include lavenders, rosemary, cistus, phlomis, fremontodendron and carpenteria.

Their natural habitat suits them for mild winters with dryish soil; they hate cold winters with alternately frozen and waterlogged soil. Wait another six weeks or so, then prune back brittle stems till you reach healthy wood nearer the base of the plant and again give them time to replace lost growth.

It’ll be obvious by then if they’re dead, as they are brown to the base – so whip ‘em out. And when choosing what to plant in their place,  it makes sense to go for bone-hardy shrubs ‘like granddad grew’ if cold winters are making a come-back. If you want to replace semi-tender exotics don’t be surprised if they are in rather short supply, since nurseries will have suffered a lot of losses too.
But look on the bright side. For years gardeners have pined for a proper winter to help kill off the slugs, snails and other garden pests; well, they won’t all have perished, but they’ll have taken a hammering this season. And anyway there’s nothing like a few gaps in the garden for giving you space to try growing something new – so be philosophical. It’s what gardeners are very good at.