House & Home

NOVICE gardeners are often scared of pruning, but really it’s very simple. Most shrubs that flower in spring and early summer do so at the ends of last season’s growth.

To keep them flowering vigorously, you do “renewal pruning” to encourage regular replacement of flowering shoots and reduce the unproductive old wood that often builds up as these shrubs mature.

This technique also helps stop the plants growing too big, and keeps them a neat and attractive shape.

WHICH SHRUBS? Renewal pruning is most commonly used for potentially large, fast-growing shrubs such as forsythia, philadelphus ( mock orange) and ribes (flowering currant). But it can also be used on weigela, kerria, deutzia, early summer-flowering spiraea, brooms and other shrubs that flower on last year’s shoots, as long as they finish flowering before mid/late July. Don’t use this method for pruning later-flowering shrubs – including roses and hydrangeas, which have their own special pruning requirements – or you’ll ruin the coming season’s flowering.

WHAT TO CHOP

Renewal pruning is like a slightly extended form of deadheading, and should be done as soon as flowering is completely finished. First cut out any dead, diseased, spindly or weak shoots. Then, starting from the edge of the shrub, take each stem in turn, and trace it down from the cluster of dead flowers at the tip to the junction with the first strong, non-flowered side shoot.

Use sharp secateurs to cut the stem off just above this shoot.

This may mean removing quite a long piece of stem, which looks drastic, but don’t worry as it’s the correct treatment.

Continue stem by stem until you have deadheaded the whole shrub.

Stack the old stems tidily to one side as you work, so they are kept well out of your way.

If mature shrubs look congested with lots of overcrowded stems, cut out a few of the thickest and oldest ones as close to the base of the plant as possible.

Look carefully before cutting and aim to thin the oldest main stems out, rather than chopping gaping holes that spoil the look of the plant. It’s also a good idea to remove one or two big branches from the centre of the shrub to let in more light and air, rather than taking out easy-to-reach stems round the sides. Stand back and study the shape of the shrub you have left.

If necessary, shorten some long or projecting stems to leave a neat, tidy and symmetrical shape.

AFTERCARE

Each spring, mulch and feed spring and early summer-flowering shrubs that need regular hard pruning, to replenish their reserves of nutrients. If feeling generous, give them a dose of liquid tomato feed in early August to promote bud initiation and better flowering next year, and don’t forget to water well if the soil is dry.

Early summer is wisteria season, when the foot-long sprays of flowers drape down dramatically from their parent vines. Wisteria is traditionally trained out across the front of large country houses, but nowadays people grow wisteria in all sorts of creative ways – over car ports and pergolas, or as an arbour. Why not plant a pot-grown wisteria now? Choose a sunny site with welldrained soil and fill it with well-rotted compost and good topsoil. Train the main stems along strong wires or poles, so they cover the required space, and shorten all side shoots to six leaves during the first summer. Once established, cut back all side shoots to a foot long every August, which may mean removing a lot of strong, tendrilly growth, then in winter go over the whole plant again. When the plant covers its allocated area, cut back the ends of the main shoots too, to keep them to size. Spiraea flowers early Philadelphus ‘Belle Etoile’ Mock Orange