Winter is a great time for gardeners to take stock, tidy up, protect plants and plan ahead. Although winter can feel like a gloomy time in the garden with the bright colours of summer a distant memory and the change of clocks bringing in darker evenings, there is still much to be done. Don’t let the cold keep you indoors; there’s plenty to do outside.
Many garden plants benefit from pruning, but it’s important to prune at the right time of year, in the right way. For many plants the right time is the winter months, whilst they are dormant. There are plenty of plants that benefit from winter pruning including summer-blooming clematis and roses, fruit trees and ornamental trees and shrubs.
Pruning is done for a variety of reasons – to promote bigger harvests, get newly-planted trees and shrubs off to a good start, thin crowded stems, train cordons, fans and espaliers, encourage flowering, shape plants, remove diseased wood and promote vigour. With a few exceptions, all of these jobs can be done in winter, when bare stems make the job of shaping shrubs and spotting diseased growth much easier.
Having established a framework, the object of pruning fruit trees is to persuade the plants to maximise fruiting. This differs with the various types of fruiting plant. Keeping fruit trees in good shape is the most reliable way to achieve high yields every year. Without pruning, apples, pears and other fruit trees can become straggly and less productive. While summer-pruning fruit trees encourages flowering and fruiting, pruning in winter controls the overall shape, size and health of your tree. This is because the trees are dormant in winter, so by cutting back branches and shoots, you are concentrating the flow of sap in spring into fewer buds resulting in stronger growth. With apples you prune to promote fruiting spurs, with pears you open up the trees to ripen the fruit.
Ornamental trees and shrubs also benefit from a winter prune, as sap is not active during the winter, cuts are less likely to ‘bleed’, and the tree or shrub sustains less of a shock than being chopped when sap is in full flow. Wounds will callous over just as they would in nature, and this natural healing process should happen before growth begins again in spring.
The first priority in any pruning regime is to remove any damaged or diseased wood. Secondly, any branches that cross and chafe should be sorted out by removing the least important bough or cutting it back lower down to an outward facing bud. Pruning out lengths of bud-bearing stems concentrates the energy of the shrub or tree into those buds that remain, so when growth starts again in the spring it will be more vigorous. However, it’s essential to make the cut in the right place. Bad pruning can result in die-back, poor wound recovery and potentially unhealthy plants. Cut back stems to just above a bud with a sloping, outward facing cut with clean, sharp secateurs to prevent the spread of diseases and ensure there is no snagging. Don’t prune too far away from the bud. This can result in the wood between the cut and the bud below dying, often affecting the health of the bud. If the bud fails to grow, die back can cause the whole stem to die.
Winter is the ideal time to assess and modify the shape and structure of almost any deciduous shrub whose canopy has become lopsided or whose branches are overcrowded in the centre. It’s a good idea to assess all your shrubs in winter, looking out for general tiredness and lack of vigour. This can often be attributed to hunger, in which case feeding and manuring in spring will help, but may also be down to the age of the stems. Shrubs like Weigela and Philadelphus benefit from having some older stems removed each year to encourage new, more productive ones to grow up. You can also do this pruning in late spring and early summer, after flowering. Use loppers to cut back these old stems either to ground level, or back to a point at which growth is emerging. Doing this annually will markedly improve the vigour of more mature shrubs.
If you haven’t already done so, move tender perennials into the shelter of a cool greenhouse, cold frame, garage or shed and cut back on watering to bring on a state of semi-dormancy. Tuberous-rooted Cannas and Dahlias should be dug up and stored in a cool, airy, frost-free place.
For those growing exotic plants outside, protect ‘hardy’ bananas and tree ferns by wrapping their trunks and crowns in straw or bubblewrap and fleece. Ensure pots and containers are not waterlogged to avoid risk of frost damage, if necessary use pot feet to raise them and improve drainage.
Prepare your lawn for winter
Help prepare your lawn for winter and keep it in good shape for spring with a few easy tasks…
• Rake up any fallen leaves, branches and any other fallen debris to prevent them from blocking out light and oxygen from the grass. Autumn leaves makeup some of the best natural, free mulch for shrubs and trees.
• Give lawns a final mow before the temperature drops. This will tidy up the garden and tackle any annual weeds that may spring up early next year. Grass will still grow in temperatures above 5℃, so don’t ignore the lawn if the weather turns mild.
• Grass can get waterlogged in wetter weather, increase drainage by aerating your lawn. Fill in the holes with a mixture of sharp horticultural sand and loam. Don’t aerate in frosty conditions.
• After aeration give your lawn a feed with an autumn lawn fertiliser, this will help make it strong enough to withstand disease over winter and give you a lush, green lawn come spring.
• Try to keep off your lawn as much as possible in winter, walking on grass in wet, frosty conditions can lead to damage that will show come spring.