Basic methods of pruning shrubs and vines

A shrub will rarely die if it is left unpruned. However, it is often desirable to control its size, to improve the overall shape, or to remove dead or diseased branches. These guidelines will show you the best way to prune shrubs and vines so they flourish.

Such pruning is basic for all shrubs. On some shrubs growth may be improved if light is let into the centre by cutting away old branches. And some shrubs will bear larger — but generally fewer — flowers if they are pruned each year. Prune selectively.

1. Pruning shears for removing shoots and small stems.
2. Long-handled lopping shears for larger stems.
3. A pruning saw for large branches. A sharp knife may also be needed for trimming around large wounds.

• When shortening branches, cut just above an outward-facing bud or shoot.
• Cut diagonally, parallel with the angle of the bud or shoot and never straight across.
• When removing entire side branches, cut a little away from the trunk or main branch.
• This minimizes the area of the cut (compared to cutting flush) and the wound heals faster.
• If the branches are large enough to need a pruning saw, rather than lopping shears, undercut the branch first to avoid tearing the bark.

Some shrubs flower on long shoots that have grown in the current season.

• To restrict their size or to encourage larger but fewer flowers, the shrubs can be pruned in late winter or spring as growth begins.
• Cut all of last year's shoots back to two or three buds or shoots from their base. Unless you want to thin out or reduce the size of the permanent framework, do not cut back into the older wood.
• After pruning, fortify the shrub by applying a cupful of a balanced organic fertilizer per square metre.
• Mulch with a five-centimetre (two inch) layer of peat moss, compost, or well-rotted manure.

The following shrubs will flower on new shoots:

• Buddleja davidii (butterfly bush)
• Caryopteris (bluebeard)
• Ceanothus (ceanothus — deciduous varieties)
• Fuchsia magellanica (fuchsia)
• Hydrangea arborescens 'Grandiflora' and H. paniculata 'Grandiflora' (hydrangea)
• Indigofera (indigo)
• Lagerstroemia (crape myrtle)
• Spartium (Spanish broom)
• Spiraea bumalda and S. japonica (Bumalda and Japanese spirea)
• Tamarix ramosissima (five-stamen tamarix)
• Vitex (vitex)

Shrubs that lose their shape, become too dense and produce fewer flowers as they mature can be pruned to good advantage immediately after blooming — each year if necessary.

1.  Cut out or shorten some of the oldest branches. Then, if the shrub is still crowded, thin out the weakest of the new shoots. Always cut just above a vigorous side branch.The following shrubs will flower on last year's wood:

• Acacia (acacia)
• Buddleja alternifolia (fountain buddleia)
• Deutzia (deutzia)
• Forsythia (forsythia)
• Hydrangea macrophylla (florist's hydrangea)
• Kolkwitzia (beauty bush)
• Philadelphus (mock orange)
• Prunus glandulosa 'Alba Plena', P. triloba (almond)
• Ribes (flowering currant)
• Stephanandra (stephanandra)
• Weigela (weigela)

• Leave most climbers and vines unpruned until they get too large; then prune them after they flower.
• Prune those grown for foliage, rather than for flowers, in spring or summer.
• Self-clinging climbers, such as the climbing hydrangea or English ivy, can be trimmed on the wall.
• Climbers on supports, such as the honeysuckle, should first be detached. Then remove lateral growths, leaving only main stems.
• If the main stems look old and woody, remove some of them and keep some of the younger ones — either the shoots growing at ground level or those low on the old stems.

Climbing plants include:

• Actinidia (actinidia)
• Campsis (trumpet creeper)
• Clematis montana (anemone clematis)
• Fallopia baldschuanica (silver-lace vine)
• Hydrangea (climbing hydrangea)
• Lonicera (honeysuckle)
• Parthenocissus (Virginia creeper)