Deadheading and Pruning Container Plants
To make sure that flowering plants continue to bloom for a long time, and to keep shrubs and climbers healthy, prolific and in good shape, you need two techniques: deadheading and pruning. Both are quick, simple and highly effective.
Snipping off fading or dead flowers is an essential way to keep plants looking good. It ensures that drab old flowers don't detract from the new — there's nothing worse than fading white flowers turning an unsightly brown. Removing them also means that plants don't pour their energy into producing seed, which is the principal aim of a flower. Instead, the plants' energy is channeled into making more, high-quality flowers for a long display.
Many shrubs and climbers need pruning to keep them vigorous and shapely and their flowers clearly displayed, and to stop their growth from becoming a tangled mess. Pruning is also essential because it eliminates weak, damaged, diseased and dead growth, so that plants put all their energy into growing strong, healthy stems. When pruning it's important to know what happens next. Usually new growth shoots out from below the cut. A hard prune generally results in a mass of new vigorous growth, while a light pruning gives more limited results. Check your plants' needs before acting.
Prune shrubs with opposite pairs of buds with a straight cut.
When to Prune
New deciduous shrubs should be pruned when dormant in winter, or after planting, to build up an attractive framework. Prune trees in winter, too, except Prunus species, which are pruned in summer. Established deciduous shrubs that flower in spring on stems made the previous year should be pruned after flowering. Shrubs that flower in summer on the current year's stems are generally pruned in early spring. Deciduous climbers are pruned likewise, depending on when they flower, and evergreens are pruned in mid- to late spring. Always use clean, sharp tools and wear protective gloves.
1. Prune shrubs with opposite pairs of buds with a straight cut (Image 1).
2. For alternate buds, use an angled cut just above a bud (Image 2).
3. Remove stems that are rubbing others, causing abrasions (Image 3).
4. Cut all dead and dying wood back to healthy growth (Image 4).
Pruning Deciduous Shrubs and Climbers
Make a downward-angled cut about 1/4-inch above a strong bud, with the base of the cut on the opposite side to the bud so water drains away from it. Try to cut above a bud pointing in the required direction. Where buds are opposite each other, make a straight cut above them.
3. Hydrangea serrata
The pruning cut on this clematis is just above a new shoot. Take care not to damage it (Image 1).
Prune mophead hydrangeas in spring, taking flowered stems down to healthy buds (Image 2).
Cut out any dead or unproductive stems right back to the base or to green shoots. Do not prune into old, brown lavender stems because they will not reshoot. Give a light all-over trim to regulate the shape. Remove any dead flowers.
2. Elaeagnus pungens
3. Euonymus fortunei
4. Gaultheria mucronata
7. Viburnum davidii
Carefully remove any dead growth in spring before the new growth develops (Image 1).
This mahonia's long, dominant stem is being cut back in spring to produce a better shape (Image 2).
Trimming Back Trailers
Trailers look most effective when they produce a bushy mass of long growth. To keep growth dense, regularly nip back the stem tips in the growing season to force buds lower down to shoot out. If a plant has become quite "leggy," with just a few lengthy, dangling stems, pinch or cut these back in spring to activate more buds lower down.
1. Campanula isophylla
2. Helichrysum petiolare
3. Lobelia erinus
Nip back the long flowering stems of shrubby, silver-leaved Helichrysum petiolare (Image 1).
Regular trimming in spring and summer helps the plant produce more trailing stems (Image 2).