Pruning Practices

• For shrubs, roses, and vines, cut about 1 cm (0.4″) above a bud or leaf.
• Roses are pruned above outfacing buds so that the centre of the plant maintains good air circulation, thereby lessening the chance of disease.
• Plants that are bare in the middle can be pruned above an inward facing bud to direct the growth towards the middle.
• Tree limbs are completely removed back to the main trunk when crossed due to friction wounds.
• Branches that form a narrow-angled crotch should also be removed, while branches forming wide crotch angles should be retained.
• Pruning paint or paste is applied to fresh cuts on branches that are 2.5–5 cm (1–2″) thick; this prevents penetration by insects or disease while the tree heals itself naturally over a long period of time.

• Fruit trees and some shade trees – These trees can be pruned in February/March before growth begins. At this time, cut close fairly quickly.
• Birch, honey-locust, magnolia, mulberry, maple, and linden – These trees bleed profusely in spring and should only be pruned in July and September.
• Spruce and fir – These evergreens do not usually require trimming, but if you need to promote density, you can cut the new growth back by half in June before it hardens off.
• Mugo and Austrian pine – To keep the growth of these evergreens thick and compact, prune a ½ to ¾ of their soft, creamy white candles in mid–late June.
• Junipers, cedars, euonymus, and boxwood – These evergreens and broadleaf evergreens put on all their growth in May and June, so you may find it easier to shape them once in summer rather than trim them in spring and then again in July/August.
• All shrubs that bloom before the end of June form their flowers the previous season on last year’s growth. This includes magnolia, forsythia, lilac, flowering quince, bridalwreath spirea, deutzia, mock-orange, flowering almond, and purpleleaf sand cherry. If you trim them in spring, you’re cutting off this year’s flowers; prune them immediately after they finish flowering.
• Summer-flowering shrubs like tamarisk, butterfly bush, rose of Sharon, weigela, hydrangea, kerria, caryopteris, potentilla, and pink-flowering spirea can all be pruned in April because they set their flowers on this year’s growth. Fall pruning is not recommended for these varieties as the new growth, stimulated by the trimming process, may not have enough time to harden off by winter. This soft tissue often dies back with cold temperature and needs to be pruned in spring.
• Clematis – Clematis has two flowering times depending on the variety: late spring-flowering clematis like Nelly Moser and the President blossom on the previous year’s wood; like shrubs, they can be pruned lightly after flowering. They will produce a second, smaller flush of blooms in September on the young wood. Summer-flowering varieties like Comtesse de Bouchard, Ernest Markham, and Jackmanii flower on new wood, grown since spring and can be pruned back to 50 cm (20″) in April. This is done to promote blooming and foliage as far down the vine as possible.

• When a plant grows too large for its space or is blocking the view from a window, it’s time to remove or restrict unwanted growth.
• Pruning dead, injured, or diseased wood is an ongoing activity.
• Trimming also needs to be done regularly when you need to maintain a specific form, such as a hedge or topiary evergreen.
• For shaping hedges, leave the bottom wider than the top, so the top growth doesn’t shade the lower.
• Older shrubs, like forsythia and lilac, which can become very dense and tend to bloom less with each year, require serious rejuvenation. Cut out about 1/3 of the stems right down to ground level to allow light into the centre of the plant, thereby encouraging new branches to grow.
• Dogwoods are loved for their yellow or red twigs in winter, but when the old wood loses colour, it will need to be removed completely. This process stimulates new growth and can be done in autumn so that branches may be used for decor.
• Fruit trees are pruned to allow as much light as possible onto each branch; more light increases flower and fruit production.

Handheld pruning shears come in two varieties:

• Bypass pruners – Scissor-like pruners that make close, precise cuts.
• Anvil pruners – These must be kept sharp at all times so the bark isn’t crushed against the bottom platform.
• Any handheld pruner will cut stems up to 2 cm (0.75″) in diameter.
• For larger branches (up to 4 cm [1.6″] thick) and roses, use long-handled lopping shears. Again, they come in a bypass or anvil variety with long handles for better leverage.
• To cut even thicker branches, use a pruning saw. The folding type is very practical, as you can safely close the sharp-toothed blade for storage.
• To make cuts higher, use a pole pruner with an extendable handle.
• Lastly, electric trimmers make quick work of shaping hedges and pyramidal evergreens.
• Manual hedge shears are better for small jobs when you need precise control.
• Keep all your tools sharp and disinfect them with rubbing alcohol to prevent the spread of disease.