Pruning trees and shrubs in the garden.
Pruning is undertaken to control growth, define shape, create flowering/fruiting branches for the following season, improve air circulation around the plant, reducing the chance of infection and probably most importantly to remove dead, damaged or diseased areas of a plant.
Spring-flowering shrubs should be pruned in late June, after flowering. Prune large shrubs quite hard, younger plants should have just the weakest growth cut back.
August is perhaps the best month for pruning, when the growth of most plants starts to slow. Pruning in August gives the plant a chance to callous over before the drop in temperature in autumn. Otherwise, prune deciduous shrubs when they are dormant in the winter and evergreen shrubs in spring, but the best rule of thumb is to prune shrubs just after they have finished flowering.
Traditionally, and you'll find it mentioned in old gardening books, when pruning trees, any new cuts larger than about 3 inches, were painted with pruning paint (such as Arbrex). The application was to seal the fresh cut to reduce the chance of infection and insect attack. However, the consensus now is that pruning at the correct time of year and leaving the cut to naturally heal over is preferable.
|Plant||What to do||When to prune|
|Acer||Prune in the winter, whilst the trees are dormant, else they have a tendency to bleed.||Winter|
|Box||Shape box hedging in the spring. Spray the hedge lightly with water first to reduce the amount of sap sticking to the shears.||Spring|
|Buddleia davidii||Left unpruned buddleias produce fewer and smaller flowers. They flower on new growth so it's best to prune in late Feb or early March before new shoots develop on existing stems. Cut all stems down to 30cm (12in), if you want to have a taller bush at the back of a border or to add more structure to the bed, leave the stems a bit longer 45-60cm (18-24ins).||Early-spring|
|Camellia||Dead head and prune after flowering in the spring.||Spring|
|Dogwood (Cornus), hazel (Corylus) and willow (Salix) that are grown for winter stem colour||
In late autumn/early winter, prune to restrict the height and width of their growth.
They respond really well to coppicing so every 2-3 years, remove all the growth above a couple of inches from the ground in Feb-March. This will encourage lots of fresh vigorous growth from the base of the plant. The following winter you'll have multiple stems with some lovely winter colours.
|Fuchsias||Prune hardy fuchsias hard in early spring. New shoots appear at the base of the plant.||Early-spring|
|Heather||Prune to the base of a flowering stem.||Spring|
|Hydrangea (mophead and lacecap)||They don't require pruning, but may need to be tidied up, or their size reduced and or restricted.
Mophead hydrangeas produce flowers from buds that formed in the previous summer. The old flower heads give frost protection to these new buds, so the plant shouldn't be pruned until all danger of frost has passed, typically this is mid to late May. Cut growth back to just above a pair of buds.
Lacecaps are hardier, so can be pruned after flowering, in the autumn.
|Lavender||Cut and shape with shears after flowering has finished, usually by the end of August. Don't cut too much into old wood as they only produce shoots from new growth.||August|
|Magnolia||Magnolias don't like being pruned. Where branches are removed, you tend to either get dieback or lots of new shoots growing. However dead or diseased branches should be removed or if the tree looks unbalanced. The best time to do this is in July to August.||Mid-summer|
|Oranmental grasses||Don't cut back, wait until spring then remove any dead growth.||Spring|
|Philadelphus (mock orange)||After flowering, cut back the stems that have produced flowers, cut these back to new growth lower down. Overgrown philadelphus should have a third of the shrub cut down to just above ground level in spring, repeat this over the following two years.||Late-spring|
|Pyracantha||Pyracantha flower on the previous years growth, so any pruning is likely to reduce the amount of berries you'll get later in the year. The best time to prune is hard in March, cutting new growth back to 10 cm in July and October.||March|
Most roses flower on new growth. In March, with shears or secateurs, as well as removing dead, diseased and crossing stems, also prune to shape and to let light and air into the centre of the plant.
Recent scientfic trials have found that one of the best methods to prune roses, to promote leaf growth and good flowering, was to wait until the end of Autumn, then cut any new growth back by half. Dispose of any cuttings in the bin or bonfire to prevent the spread of diseases.
Miniature roses: Only remove dead and or diseased growth, trim to shape and deadhead. Use scissors, as using your hand or secateurs may damage the plant.
|Wisteria||Prune wisteria twice a year, in February and July, cutting back to 7 spurs in Feb and 2 spurs from the main stem in July (hence 7 in 2 and 2 in 7). The July pruning exposes the wood to the sun, which then bear next years flowers, cut back to 9in of old wood and tie any laterals in horizontally. Beware that the sap can stain clothing.||February|
|Clematis - spring flowering (including alpina and macropetala)||Prune early, spring-flowering clematis after flowering, this allows plenty of time for the stems to regrow during the summer, which will bear flowers the following year. Leaving the pruning until later won't cause any huge problems, just fewer flowers next year. They can sometimes get a bit boisterous, rather than extensive pruning, tidy them up once the flowers have finished.||May|
|Clematis - summer flowering||Prune summer flowering and fast growing, large flowered hybrid clematis varieties like 'Jackmanii' in February, as they flower on this year's growth. To keep the flowers appearing low down, where you can see and appreciate them, cut them back hard, to a couple of inches of the ground if they are really overgrown.||February|
|Clematis - viticella varieties||To keep them compact and tidy. Prune in March to 20cm (8in) above ground level.||March|
|Fruit||What to do||When to prune|
|Apple and pear||
The best time to prune is in Jan-Feb when the trees are dormant. First remove any dead, diseased or dying branches, including any that are showing signs of canker, then remove any that are crossing or rubbing.
Remove congested branches from the centre of the tree, leaving 4 to 6 of the strongest branches, to try and create a goblet shape, this lets air into the centre encouraging a healthy tree and reducing disease.
Reduce the length of the remaining branches by removing a third of last season's growth. Prune any shoots from the main branches to 6in (15cm) in length, leaving 6-8 flower buds, from which the fruit should form.
Summer prune fan or espalier trees in late July to force the plants energy into the fruit. Prune side shoots to two or three buds.
Remove suckers growing around the base of apple and pear trees. These are from the rootstock the apple or pear trees are grafted onto, sending up new shoots.
|Apricot||They require very little pruning. Remove dead, damaged and diseased branches in the spring and thin and train branches in the summer.||Mid-summer|
|Blackberry||Blackberries fruit on last seasons growth, prune out fruiting branches after fruit has been picked, remove all but the the 6 strongest new branches, tying these to supports for next year's fruit.||September|
|Blackcurrant||Blackcurrants fruit on newer growth, ideally two-year old stems. On two year and older bushes, cut out a third of the oldest stems (these should be darker/blacker than the new growth which is a pale brown colour) to a couple of inches above ground level from late autumn into winter. Another method of pruning is to cut the stems of fruit bearing branches at harvest time (August), you can then collect the fruit more easily, although this might reduce the size of the crop in subsequent years.||September|
|Damson||Pruning won't improve the crop. If you have branches that are in the way of other plants or give the tree an unbalanced look, remove them, but otherwise just remove dead or diseased branches. Pruning is best left until late June or July to reduce the chance of excessive 'bleeding'.||Mid-summer|
|Fig (Ficus carica)||Prune trees in April just before they begin to start vigourously growing again. Remove any dead, diseased and crossing branches, prune the rest of the fid as hard as necessary to maintain size. Bear in mind that the fruit forms in the previous autumn on that seasons growth, so don't remove branches that carry these small fruit. With fan-trained plants remove a quarter of all stems, back to a couple of inches of the main trunk, also removing all branches that are growing away from the wall or fence.||April|
|Gooseberry||Gooseberries fruit on spurs on two-year and older wood, remove crossing branches, trying to create a goblet shape. Followed by cutting off a third of the length of remaining stems. In mid-June remove any new shoots from the centre of the bush to reduce sawfly damage and allow plenty of air around the plant to reduce the chance of disease. Sawfly lay their eggs in the centre of the bush, when the caterpillars hatch they will start with the fresh growth before moving on to the rest of the plant.||October|
|Grapes||Prune grape vines in late November or December. Cut back last year's growth to one or two buds, removing the majority (80-90%) of the old growth,. This encourages new shoots which will bear the next season's fruit.
The old dead bark on the trunk should be gently scraped back to removing hiding places for any pests, such as mealybug and fungal spores.
When the bunches of grapes begin to form in the summer, remove half of them to encourage the remaining fruit to swell and ripen.
Note: Pruning a vine at other times can lead to severe bleeding of the plant.
|Passion flower||Passion flower should be pruned in the spring.||Spring|
|Pear||See Apple and pear above||Winter|
|Raspberry - autumn fruiting||
Autumn fruiting raspberries fruit from the current season's growth. In October, cut all canes that have fruited, along with any that are damaged or diseased almost to ground level (4" / 10cm) before tying in any new fresh growth ready for next years fruit.
|Raspberry - summer fruiting||Summer fruiting raspberries bear fruit from one year old growth. In mid-autumn prune the old branches that have borne fruit this season, almost to ground level (4' / 10cm).
In mid-summer prune out younger shoots at ground level to leave 15cm (6in) space between them.
|Red and white currant||Red and white currants fruit on old wood. In March, cut back the main stems by a half and cut any new laterals to 1-2 in of last year's growth. Also thin out or remove any weak branches.||March|
|Rhubarb||Whilst not technically pruning, to stop rhubarb getting too congested. In October, lift the crowns every 4-5 years and divide. Split the crown into 3 or 4 pieces with a spade so each part has a 'eye' shoot and then replant the chunks a couple of feet (60cm) apart.||October|
|White currant||See Red and white currant.||March|