Pruning:

There are several reasons one would endeavor into the pruning of trees, shrubs, and groundcovers. This is a reasonably extensive topic, and we will give some basic guidelines.

Pruning equipment:

By-pass loppers: By-pass loppers are typically used for selective pruning of large branches of +/- ½” or larger. Many types of loppers can cut limbs or branches up to 1 ½” diameter.
By-pass hand pruners: By-pass hand pruners are typically used for the selective pruning of limbs and branches smaller than +/- ½”.
Saws: Saws are used in most cases for pruning limbs and branches to large to prune with other types of pruning equipment. There are a variety of saws that are available. A folding saw will do the job quite well and be very versatile.
Shears: Shears, whether hand or power, are for the wholesale pruning of plant material. They are the fastest way to prune or shape shrubs with narrow branches or limbs. Shears are also the least selective way to prune and could contribute to long-term stress on the plant resulting from cuts, which are not clean.
Pole pruners: Pole pruners afford the opportunity to prune large shrubs or small trees without the need of a ladder. Pole pruners typically incorporate both a by-pass lopper and a saw, and are extendable.

In all cases, your pruning equipment should always be SHARP AND CLEAN before beginning your pruning. Please invest in quality equipment. Good equipment will last you a lifetime and reflect in the overall results of your pruning.

Pruning techniques: Generally speaking, it is better to prune with loppers or hand pruners than with shears. Shears do not always make a clean cut and you are not taking into account cutting above the nearest bud or node. When pruning small branches, make a clean diagonal cut just above a node or bud. It is very important to make a cut clean and not tear the bark. Tearing the bark may not only scar the plant, but also make the plant susceptible to insect or disease by opening up the outer tissue of the plant, similar to cutting your skin.

When cutting a large branch, prune the limb as close to the trunk as possible with the blade of the pruners or loppers against the trunk. Pruning large limbs may require more than one cut to prevent the weight of the branch from causing the bark to tear when the limb falls. In this case, cut the majority of the branch approximately 12” above your final cut. Once this cut is made, remove the remainder of the stub.

If you are using a saw to prune, it is extremely important to use good technique to keep from causing extensive damage to the bark of your tree or shrub. ALWAYS make a small cut with the saw on the under side of the limb as close to the trunk or main branch as possible. This will prevent the limb, as it falls away from the plant, from tearing away the bark. Then proceed with cutting the limb on the topside attempting to meet your previous cut on the bottom. If possible, try to hold the limb so it does not fall away and damage the remaining plant.

Pruning for transplanting: Should you desire to transplant a tree, shrub, or perennial in your garden, it is likely that significant pruning will need to take place. By transplanting the plant, you are removing a large portion of the root mass. Usually, the roots that are removed are the roots that are primarily responsible for feeding and watering the plant. Because of this, the foliage of the plant, typically referred to as the head or canopy, must be reduced because the new root mass is not able to support the existing volume of foliage. Before beginning to dig, prune the head of the plant. Expect this pruning to be severe. Once the plant begins to establish, it will flush out new growth and likely return to its former self.

Pruning for shaping: Pruning for shaping should be done selectively. Unless developing a topiary, bonsai, or hedge, pruning should be performed to enhance the natural growth development of a plant and not to alter it. Cross branching, especially in small ornamental trees and large shrubs, should be removed. This will prevent the branches from eventually rubbing against one another and causing damage or death to all or part of the crossing limbs. In many cases, only one of the lateral crossing limbs is removed.

It is common practice to limit the size of a shrub or tree. This should be done judiciously and performed with all effort to maintain the natural growth habit of the plant. A typical result from over pruning or ‘topping’ of a plant is the development of ‘suckers’ from the base of the trunk, the trunk, or limbs. These should be removed immediately and not allowed to mature.

Hedge pruning is usually done with shears. In this practice it is common to ‘top’ a plant and cut its side close to achieve the desired effect. Ideally, the more dense the hedge is, the more appealing. This effect can still be achieved using hand pruners instead of shears. It’s true this exercise will be more time consuming, but the end result is more pleasant. While pruning the hedge, take into consideration developing ‘invisible’ holes in the foliage to allow sunlight in to the center of the plant thus allowing more foliage development. Ultimately, your hedge will be denser than had you used shears.

If pruning an overgrown shrub, such as a taxus or yew, to reduce its size, be patient. Plan to reduce the overall size of the plant in a time frame of 1-3 growing seasons. Use the previously described method to selectively prune ‘invisible’ holes in the foliage. Expect to take approximately a fourth to as much as a third of the plant in each pruning event. The plant will recover more quickly than had you taken a significant volume of the foliage and be more visually appealing in the process.

There are some shrubs, such as Spirea, that can be cut back every year, much like a perennial, to maintain the optimum size and shape.

Pruning to promote growth or for plant health: Pruning inevitably promotes growth development in plants. This may be very beneficial, especially with old or oddly shaped plants in the landscape. Selectively prune the foliage you would like to remove to shape the plant or add symmetry. You can expect the plant to flush and add new growth within that growing season.

For health’s sake, remove dead, diseased, or broken limbs as soon as possible. For some diseases, should your plant become infected, it is better to prune when your plants are dormant, late fall through winter. Should you plant(s) become infected, consider having them professional diagnosed.

Pruning time frames for shrubs and trees: The best time to prune shrubs and trees depends on when they flower.

Shrubs and trees that develop blossoms on new growth in late spring or summer should by pruned in either early spring, or the last few weeks of winter. Those shrubs and trees would include:

Barberry
Butterfly Bush
Beautyberry
Caryopteris
Clethra
Rose of Sharon
Hydrangea
St. John’s Wort
Japanese Kerria
Privet
Honeysuckle
Sumac
Roses
Willow
Spirea

Shrubs and trees that bear blossoms on last year’s wood should be pruned soon after blooming. Flower buds, in this group, are formed late in the previous growing season. Heavy pruning in the late winter or early spring will dramatically lessen the flowers to be enjoyed in the spring. The shrubs and trees in this group include:

Azalea
Pea shrub
Redbud
Quince
Fringe Tree
Deutzia
Forsythia
Magnolia
Mock orange
Currant
Climbing Roses
Spirea
Lilac
Rhododendron

Some shrubs and trees should be pruned lightly after blooming and again lightly in early spring. Those shrubs and trees include:

Dogwood
Honeysuckle
European Viburnum
Weigelia
Inkberry

Most trees can be pruned any time during the growing season. If the pruning is to be severe, try to spread the pruning out over several growing seasons, if possible, to limit any stress the tree may experience.

Pruning of perennials: Many perennials simply disappear after we experience a few hard frosts, hosta for example, and may require little to no pruning at all. Some perennials may be left all winter for visual interest. This is at your discretion. If you find the dry vegetation in winter more appealing than empty beds, leave the foliage until late winter or early spring. Make sure to remove all of the dried vegetation before the next growing season begins. A few of these plants would include ornamental grasses, coneflower varieties, and Black-Eyed Susans.

For most perennials the dried vegetation can and should be removed in late autumn or in the winter months to prepare for the next growing season, this would include bulbs. When the foliage on bulbs begins to discolor, it can be cut away. Be careful with perennials that are semi-evergreen such as coral bells to not damage the plant.

‘Deadheading’ or pruning of perennials after they bloom may promote additional blooms throughout the growing season. In many cases, it will prevent the perennial from becoming floppy.