Trimming off withered blossoms and tattered stems does much more than make your garden appear neatly groomed. It also coaxes plants to produce more stems and blossoms, extending the flowering time of many plants. While most perennials and shrubs will bloom all at once no matter what you do, and some plants can shed their old flowers without aid, most annuals and a few perennials depend on you to relieve diem of old flowers. When deprived of the opportunity to produce seeds, annuals have no choice but to flower again and again, in an attempt to set seeds.
Often called deadheading, this operation is best undertaken with a sharp pair of handheld pruning shears. Scissors work well, too, provided the stems arc not extremely woody or tough. The objective is to make swift, clean cute without twisting or pulling on the plant. Gather your trimmings in a small pail,
along with any leaves that appear yellow, spotted, or brown around the edges. If they appear old and uttered add them to your compost pile; if any leaves appear to be diseased or insect infested, dispose of them in the trash.
The Art of Smart Pruning
Many gardeners are entirely too eager to prune shrubs and trees, which is a way of inventing unnecessary work. And, while most woody plants do benefit from pruning at some time in their lives, you should always have a clear purpose before you embark on a pruning campaign. Until you have a definite objective in mind, it is usually best to content yourself with observing the plant a while longer Then, begin pruning when you know exactly what you hope to accomplish, such as removing crossed or damaged branches or shaping the plant and it is important to prune at the right time of the year to prevent winter frost damage to new growth initiated by pruning in the fall, or to keep from cutting off next year's flower buds.
There are many good reasons to prune, and in fact some plants can never reach their peak of health and beauty without regular, thoughtful pruning. Consider the following valid reasons to prune, and compare them to the pruning needs you see in your yard. Then choose from the techniques described in this section to do the job right. * REMOVING dead or diseased plant parts. Any time is a good time to relieve plants of stems or branches that have died or seem to be in the process of doing so. By midspring you should be able to identify plant parts killed by winter's cold. An easy way to determine if a branch is dead is to scrape away a small piece of bark. If there is a layer of green tissue just beneath the bark, and the branch is flexible and not brittle, the branch is alive.
Shaping a plant to improve its structural strength. This is the real purpose behind pruning young trees, and you can also prune some shrubs to bring out the best in their natural shapes. However, every young tree does not need this type of pruning. Only those with branches that cross or rub against each other, causing wounds that are entry points for disease; those with very acute crotch angles (which tend to split in storms), or trees in which you wish to eliminate low-hanging branches, or dense shrubs that need to be opened up, such as a rose, to allow light and air to reach the center where it will discourage
fungal infections. Opening up a mature tree is called creating windows in the canopy, and it is a natural-looking way to admit light into a garden area or to allow homeowners to enjoy a view without losing their tree. Structural pruning of shrubs is usually done for artistic reasons, for example training an azalea to look like a small tree, or accentuating the sinewy curving trunks often found on rhododendron, smokebush, and witch hazel.
Pruning to promote better flowering. When left to their own devices, many shrubs will grow foliage so dense that flowering suffers. Roses are an excellent example, particularly reblooming roses, such as hybrid teas. Other reblooming shrubs, such as blue-beard and buddleia also flower more and longer when old branches are headed back. Yet this pruning goal is not limited to reblooming plants. Thinning out old branches from forsythia, hydrangea, lilac, and mahonia greatly improves the vigor and flowering performance of the healthier branches that remain on the shrubs. Up to a third of the branches can be removed from a shrub each year without affecting its appearance or health.
Pruning to rejuvenate old plants. Old age is relative where plants are concerned. Young or old, blue-beard grows best when it is cut back nearly to the ground each spring, and buddleia grows back best from a 1 to 2 ft (30-60 cm) tall stump. With red-osier dogwood, the best stem color develops on 1 and 2 year old stems, and cutting out old ones is the best way to keep plenty of new ones coming on. As for huge old shrubs that need large-scale renewal, the best approach is to thin out old branches gradually, over a period of two to three years.
Eliminating hiding places for pests and diseases. Do not hesitate to prune off limbs or branches that are riddled with holes that are oozing sap, or are surrounded by sawdust, which are made by boring caterpillars. Plant tissues that are badly damaged by these pests seldom recover completely, so there is little reason to prolong the plant's suffering. Also trim off and dispose of branches that are disfigured with corky looking galls, or any that appear hopelessly lost to mildew or fungal leaf spot diseases.
Pruning Techniques
There are three basic techniques for pruning plants: thinning, heading back, and shearing. It's important to understand the difference between these techniques, because the easiest method, heading back, is seldom the best.
Thinning is what you do when you follow a branch or stem back to where it sprouts, and prune it at its point of origin. With trees, this is usually where it emerges from a larger branch or the trunk. But in the case of long-limbed shrubs, such as forsythia and mahonia, most stems originate right at the ground. Spend a few minutes studying where branches originate and you will know exactly how to do this type of pruning. Always make pruning cuts at an angle to the stem to allow water to drain from the cut surface to keep it from rotting. Although thinning is often a slow and awkward way to prune, it is the best way to preserve the natural shape of any woody plant.
Heading back a technique that involves pruning off the tips of branches, which causes buds farther down the branch to develop into new stems and flowers. This type of pruning increases the number of branches, making a plant bushier. It is used mostly for plants that bloom on stem tips, such as buddleia, rose, and most perennial vines. Deadheading, or removing the spent flowers, of annuals and perennials uses this same principle. Because heading back is easy compared to thinning, many gardeners mistakenly head back azaleas, forsythia, and hydrangea, robbing the plants of their natural beauty as well as many future flowers.
Shearing is wholesale heading back, and its use should be limited to plants you wish to grow as
dense hedges, for example barberry, boxwood, holly, and other shrubs that have a tight, compact form. Yet do keep in mind that just because a shrub can be sheared does not mean that this is necessary. When dwarf cultivars of shrubs are chosen, often little or no pruning of any kind is needed to keep them shapely and attractive.
Plant Pruner's Toolbox
Pruning cuts should always be smooth rather than having ragged edges, so sharp tools are essential.The following four tools can handle most pruning jobs in a home landscape.
Pruning shears use a scissors action to cut through stems less than 1/2 in (1 cm) thick. Light thinning and heading back, including deadheading of flowers, can usually be done with pruning shears. There are two styles, anvil pruners and bypass pruners. Anvil pruners have one blade that presses a branch against an "anvil," and cuts through it. Anvil pruners are often less expensive than bypass pruners, but if you use them, you run the risk of damaging a branch by crushing the cut edge, leaving an unattractive cut that is open to disease. Bypass pruners are generally preferred, because they have two cutting blades that work together like a pair of scissors to make a sharp, clean cut.
Loppers are long-handled pruning shears that can cut through woody stems up to 3/4 in (2 cm) thick. They are the tools of choice for thinning branches from shrubs or for removing long suckers that often emerge from the bases of trees.
A pruning saw is needed to cut through woody tree limbs, or to prune shrub branches more than 1 in (2.5 cm) thick.This saw is also available in a long-handled version for cutting tree branches that are beyond a gardeners reach. Handle with care, because pruning saws have deep, sharp teeth. 0
Hedge trimmers make fast work of shearing plants. Hand-operated hedge trimmers are fine for small jobs, but if you maintain a large hedge you will find electric or rechargeable, battery operated models a true joy to use.
How to Prune Heavy Tree Limbs
If you look closely at the place where one tree branch joins a larger one, including the trunk, you will see a wrinkled raised collar of bark. Strive to make pruning cuts just outside this collar, without cutting into it. This is because the collar contains chemicals that the tree uses to wall off the injury (your pruning cut), making it naturally impervious to invasion by pests and diseases. Tree experts no longer recommend painting a pruning wound with tar or paint, which can trap moisture, inviting rot and disease.
If the limb is a large one, begin by cutting it off about 6 in (15 cm) from the branch collar. To keep the weight of the limb from binding the saw blade, first make a small cut on the underside of the branch. Then cut off the limb starting from the top edge of the branch, about 1 in (2 cm) beyond the cut on the branch underside.
Remove the stub by making a single downward cut just outside the branch collar.
Entries (RSS)