Age-Old Wisdom meets Modern Tools
Pruning trees and shrubs may be the most feared act in gardening. Using sharp metal objects to cut away life goes against our natural inclinations.
There is probably no gardening task that generates as much fear in home gardeners as fruit tree pruning, and because of this, many homeowners want to ignore it.
However, if you ignore pruning, your trees will only get worse.
First, remember that Nature is the “Great Pruner.” For example, when trees grow too close together, branches die as they compete for sunlight and airflow.
Second, pruning is a vital part of gardening. The key is to know why we’re sharpening our shears. Do it! Consider these three reasons:
1. To Thin:
Remove to improve.
- Thin all dead, diseased, broken and injured parts. This pruning can be done any time.
- Thin branches that hang down below the horizon line, or “hangers,” are generally not productive and should be removed as well. Prune any limbs that sag or grow close to the ground.
Thinning prevents confusion of a plant’s structural line and enhances it health.
- For young shrubs, “heading cuts” remove part of a shoot or limb and encourage side branching and dense growth. With hand pruners, trim long, unbranched stems by cutting just above a healthy bud, angled at 45 degrees and facing away from the bud. Note that new shoots will grow in the direction the bud is pointing. Like most pruning, heading cuts should be timed to avoid disrupting the plant’s flowering.
- As a shrub develops, thin out old, weak, rubbing, or wayward branches where they merge with another branch. This opens up the middle of the plant to more sunlight, which keeps interior branches healthy, stimulates growth, and increases flowering. Thinning cuts remove an entire branch where it meets another limb, the main stem, or the ground. They should be made as close to this junction as possible. These cuts help maintain the plant’s natural shape, limit its size, and open up the interior branches to light and air.
- Older shrubs may need a more extensive program of thinning cuts that takes three years. On shrubs with multiple stems that grow up from the base, like lilac, viburnum, forsythia, and dogwood, remove ⅓ of the old stems each year while leaving the new, flower-producing growth untouched. Eventually, the new flower-producing stems will completely replace the lackluster old growth.
2. To Reduce:
In Nature, most plants we grow are in splendid isolation, trying to spread unnaturally fast. Our job is to prevent certain shrubs and trees from outgrowing their position in a yard.
- Remove all suckers and water sprouts. Suckers grow from the base of the tree. Water sprouts are succulent growth from the previous year and usually shoot straight into the air from more established scaffold branches. Water sprouts compete for light. They are not productive and should be removed. They are best controlled in the summer when they are only 2 to 4 inches long. They can be easily removed by rubbing or breaking them.
Judicious reducing helps plants develop into sound structures without over-stressing their limbs. Also, maximum flowering and bountiful fruit are only possible by pruning.
- For fruit trees, it’s necessary to prune branches to support the weight of fruit. Also, fruit trees that have shaded interiors are far less productive than those that receive proper sunlight. When leaves receive sun exposure, more carbohydrates are made. This sends more sugars to the fruit.
- Know where the fruit is formed. Peaches are formed on last year’s branches—and should be pruned severely to stimulate enough growth this year to support fruit next year. Apples, pears, cherries and plums are all found on short, stubby branches called spurs—typically formed on wood that is 2 to 5 years old. Prune less drastically to reduce the amount of vegetative growth or water sprouts.
It sounds harsh, but severe pruning is necessary to restore older trees and shrubs to better health. Most plants are amazingly forgiving with experimentation. Think twice, cut once, and watch carefully. Your plants will tell you in their own way how to do better next season.
- When cutting a tree branch, cut as close to the branch collar—the swollen ring of bark where the limb meets the main stem or trunk—as possible without cutting into it. When cutting branches more than 1 inch in diameter, avoid tearing or stripping bark by using a pruning saw and the three-cut method shown below. A good pruning cut will heal quickly and naturally without the use of dressings or poultices.
- Neglected deciduous shrubs can often take hard pruning, as will a handful of broadleaf evergreens, such as privet. Using loppers and a pruning saw, cut back all stems to within an inch of the ground during the plant’s winter dormancy. Come spring, the plants will quickly produce new shoots from the base. Of course, this technique will leave you with little to look at while waiting for the new growth.
10 Pruning Pointers
- Prune summer-flowering plants, which will flower on the coming season’s new growth, while they are still dormant (late winter and early spring). Plants are dormant but the coldest part of winter has passed, lowering the chance of cold damage near pruning cuts. See our pruning chart for summer-flowering shrubs and trees.
- Prune spring-flowering plants immediately after their blossoms fade. Because they produce flowers only on old growth from the previous season, pruning soon after bloom will maximize flower production the next year. Pinch the candles on whorled-branching conifers when you see new growth. See our pruning chart for spring-flowering shrubs and trees.
- Prune butterfly bush severely. These plants bloom only on new shoots. Stimulate new growth by lopping the whole plant to within a few inches of the ground.
- Cut to the ground some or all of the oldest stems of shrubby dogwoods. This will make way for the youngest stems that will provide next winter’s show of bright yellow or red.
- On apple and other fruit trees, cut water sprouts right to their bases. These vigorous, upright shots soak up the plant’s energy and bear few or no flowers or fruits. Remove weak twigs.
- For smooth hydrangea, cut all stems to the ground. For bigleaf or oakleaf hydrangea, cut stems with old flowers still attached back to fat flower buds.
- For lilacs, remove all dead canes. Cut out all crossing branches, keeping the strongest or most useful ones for a graceful form. Cut back last year’s growth dramatically, though never more than one-third of the live wood.
- Avoid pruning a young or newly planted tree — it needs as many leaves as possible to produce the food required for good root growth.
- Always prune back to a healthy stem or branch without leaving stubs. This eliminates hiding places for pests and diseases, and looks better.
- Never cut back the plant’s leader—the top-most growing point of the tree—which is vital to letting the tree develop its natural form.
Enjoy our gardening expert’s article with more advice on when to prune trees and shrubs.