In early spring, it’s a good idea to assess your garden to see what Mother Nature has done during the winter months. Now is the time to remove any weak, damaged or infected branches. If you have spring blooming shrubs and trees, you may want to wait until after they bloom to do any additional pruning.
The late dormant period in early spring is a good time to prune deciduous trees and shrubs because there’s no foliage on them, which makes it easy to see the plant’s framework and identify which limbs or branches need to be removed. Also, the wounds caused by pruning heal faster in the spring and insects and diseases are less likely to be a problem. Pruning–done the right way–can invigorate a tree or shrub: you’re removing dead or diseased wood, improving air circulation in the interior of the plant, and helping to increase flower and/or fruit production.
Before you begin pruning, step back, look at your tree or shrub and take note of the shape. Notice whether it is misshapen, and visualize the shape it should be.
When removing a branch, don’t make cuts that are flush with the trunk. These kinds of cuts make large wounds and destroy the tree’s natural ability for rapid healing. Make the cut just beyond the branch collar which is the swollen ridge at the base of the branch. This collar area contains the tree’s natural defense mechanisms and promotes the healing process. In time the collar will grow a callus and heal. If you cut off the branch collar, the wound won’t heal properly and that can be disastrous for a tree. For large limbs, use the three-cut method:
Prune from the inside out and from the bottom up. Make thinning cuts first, heading cuts last. Heading cuts are made to shorten the tree, to head it back and in the process stimulate new growth. Keep heading cuts to a minimum. There are two types of heading cuts: selective and nonselective. In a nonselective cut, ordinarily used to shear formal hedges, branches are cut back partway, which results in rapid, bushy growth just below the cut. This cut is not recommended for trees because it often results in a “lollipop” look. Selective cuts reduce the overall size of a tree without changing its natural shape. Make these cuts directly above a bud or side branch that allows for outward-facing growth.
Although spring is the best time to prune most trees, there are exceptions. Don’t prune oak trees before midsummer in our area. This is important to prevent the risk of spreading oak wilt, a serious disease affecting oaks in some regions.
You may find some trees, such as maples, elms, and birch, bleed heavily when they are pruned in late winter or early spring. It’s best to prune these trees in midsummer. But if you do have to do some damage control in spring, don’t worry, the sap flow will eventually stop.
Many of the reasons to prune trees also apply to shrubs. Younger stems ( 2 to 5 years old) generally produce more flowers and/or fruit. Removing thin, spindly growth tidies a plant’s appearance and reduces its size. In addition, pruning out drab, older stems on plants like red- and yellow-twigged dogwoods allows for more vibrantly colored growth. Most deciduous shrubs can be pruned drastically, if needed, to either rejuvenate or control the size of the plant.
Shrubs to prune now: Abelia, Barberry, Clethra, Cotoneaster, Crape Myrtle, Deutzia, Redtwig or Yellowtwig Dogwood, Itea, Potentilla, Rose Bushes (except climbers), Rose of Sharon, St. Johnswort, Smoke Tree and other summer or fall bloomers.
NOTE: Hydrangeas may be either spring or summer bloomers. Some varieties bloom on previous year’s growth while others bloom on new growth (a few of the newer varieties bloom on both). If you are not sure what type of hydrangea you have, do not prune the tips at all – you may end up cutting off all of this year’s flowers. You may remove selected old stems to the ground to rejuvenate and maintain a smaller size. Since hydrangeas are particularly susceptible to winter freezing and are also slow to come out of dormancy, wait until the end of May before deciding how much dead wood to prune away.
Coniferous (cone bearing) evergreens are characterized by growth that is either whorled (such as spruces) or random (non-whorled, i.e. arborvitae). The term broadleaf is used to include all evergreens except conifers (holly, boxwood, etc.). Most broadleaf evergreens are best pruned after they flower in the spring. Those that may be pruned in early spring include boxwood, euonymus, pyracantha and any of the hollies. Most conifers (arborvitae, false cypress, fir, hemlock, juniper, pine, spruce, yew) can be pruned in the spring and then pruned again in the summer, if needed. If tip-pruning whorled conifers in the summer, prune when the new needles are one-half their mature size. When the new needles mature, the cut marks won’t be noticeable.
When pruning pines, make pruning cuts just above the needle whorls. Most new lateral growth is stimulated at these points rather than along the stems between the whorls. With most other needled and broadleaf evergreens, cuts can be made at any point along the branch, but care should be taken not to cut too far back into the older, bare wood because new growth is not as readily produced from such wood. When selectively pruning, it is a good practice to cut the growth back to a side shoot and an outward facing bud. Some evergreen species withstand relatively heavy pruning. This is true of plants such as yew, boxwood, Japanese holly and hemlock. These plants can be sheared, which involves the uniform removal of new growth to make a plant conform to a prescribed shape. Because shearing encourages the formation of additional lateral growth, a more dense habit of growth is created. Keep in mind that a perfectly manicured shrub requires more time and effort to maintain than a naturally shaped one needing occasional pruning. However, the best way to keep pruning to a minimum is to purchase a plant that will grow within the space that you have!