A majority of trees and shrubs grow just fine without any pruning. If you like the natural growth, don’t prune, just remove any dead, damaged or diseased branches. However, some basic pruning can certainly enhance the appearance of your plants in the landscape. Here is some basic information and a few steps to follow to help you achieve the best outcome. When to Prune Identify what type of shrub you have and when you should prune it. 1. Spring-flowering shrubs such as forsythia, lilac, azalea, mock orange, bigleaf (mophead) and oakleaf hydrangea, deutzia, quince, some viburnums, spirea and weigela all bloom on last year’s growth (old wood). These plants should be pruned right after blooming to give them time to put on new growth and have it harden off before the next winter. 2. Summer-flowering shrubs such as bluebeard shrub, butterfly bush, crape myrtle, sweet shrub (Calycanthus), summer sweet (Clethra), panicle hydrangeas, Rose of Sharon, oleander and late-blooming spirea all bloom on new growth from the current season (new wood). These should be pruned in late winter to early spring, before new growth starts. 3. Reblooming shrubs bloom on “old wood” and “new wood” so if you choose to prune, do so immediately after the first flush of blooms. This will allow you to enjoy the spring blooms and give the shrub time to put on new growth for any secondary blooming. 4. Broadleaf evergreens like holly bloom on “old wood”. You can prune in late winter, but be mindful that you are sacrificing blooms and the decorative berries that follow. The trade-off is that late winter pruning is less stressful for the plant than pruning at other times of the year. If you are growing the plant for its berries, it is perfectly fine to wait until after the berries form to prune. Azaleas and rhododendrons should be pruned when they have finished flowering in spring. Other broadleaf evergreens such as boxwood and Japanese holly and needle-type evergreens can be pruned in late winter or early spring before the new growth matures. They can also be pruned during the semi-dormant mid-summer period. Lastly, it’s okay to prune anytime. You may sacrifice some color for a season, but in the long run, you are not hurting anything. Your shrubs will be just fine. How to Prune 1. Deciduous shrubs For a natural appearance, use sharp bypass hand pruners and loppers. Keeping the plant’s health in mind, only remove up to one-third of the branches at one time. Use hand pruners to cut branches up to ½" in diameter. For branches ½" to 2" in diameter, use loppers. For all branches over 2", a hand or bow saw is most effective. Cut each branch to a big healthy bud that is facing the outside of the shrub. This will ensure that any branching from this cut will grow toward the outside of the shrub and keep good air circulation in the center of the shrub. The angular slice allows the branch to heal quickly and prevents potential disease and fungus from forming on its surface. Although pruning paints and wound dressings were commonly used to seal pruning cuts in the past, they are no longer recommended. Plants perform best when pruning cuts are allowed to heal on their own. If the shrub you are pruning is a fairly fast grower, prune to a height 6-12" shorter than you want the shrub to be to allow for new growth. Vary the heights of your cuts to create a natural effect rather than a sheared look. Some shrubs have been grafted onto other rootstock. Suckers are the shoots that may grow below the graft or bud union. This undesirable growth will be different than the original shrub and should be removed as close to ground level as possible. There may also be water sprouts. Water sprouts are vigorous shoots jutting out from the trunk or older branches that are not characteristically like surrounding branches. These should be removed so the shrub’s energy is devoted to growing healthy limbs. Cut back water sprouts as short as possible without damaging the base of the limb. If deciduous shrubs have grown for several years without pruning and become overgrown, it may be necessary to do a rejuvenation or renewal pruning. Gradual rejuvenation pruning involves thinning out one-third of the large limbs by cutting them to the base of the shrub, repeating the process each year for three years. This method works well with shrubs that have multiple stems coming from ground level like lilacs, forsythia and red twig dogwoods. A hard pruning or renewal pruning involves cutting all branches to about 6-12" from the ground. Shrubs that react well to this type of pruning are spirea, potentilla, lilac, forsythia, mock orange and weigela. Shrubs that have one tree-like stem coming from the ground or ones that have been grafted should not be pruned with the hard pruning or renewal method. 2. Broadleaf evergreens and needle-type evergreens Broadleaf evergreens like holly should be pruned using hand pruners instead of shears. Hand or electric shears damage the foliage, leaving brown edges. Start with the tallest limb you want removed and go from there, stepping back to take a look at the symmetry to make sure you end up with a balanced look. Azaleas and rhododendrons can be pruned after they have bloomed in spring following the same steps for pruning deciduous shrubs. Needle-type evergreens can be pruned one branch at a time for a natural look or cut back with shears to create a dense formal shape or hedge. Prune so the base of the shrub is wider than the top. This allows sufficient sunlight to reach the bottom of the shrub for healthier growth. Yew, hemlock and arborvitae are examples of evergreen shrubs that will generate new growth on “old wood”. New branches will develop from concealed buds in the crotches of branches. However, if you cut too deep into the “dead zone” where sunlight has not reached the center of the shrub for years, it will not generate new growth. For evergreens like pine, spruce, fir and junipers, tip pruning (only removing the new growth) in spring is best if you prune at all. Needle growth is arranged in clusters along a twig with new growth at the tips. Don’t trim back into the woody stems where there is no green growth as new growth will not develop there. Suggested Pruning Time for Common Flowering Shrubs PRUNE AFTER FLOWERING: • Azalea • Beauty bush (Kolkwitzia) • Bigleaf Hydrangea (Hydrangea macrophylla) • Climbing Roses • Deutzia • Doublefile Vibernum • Elderberry (Sambucus) • Flowering Almond • Flowering Cherry • Flowering Quince • Forsythia • Honeysuckle • Japanese Kerria • Japanese Pieris • Koreanspice Viburnum • Lilac • Loropetalum • Mock orange • Ninebark (Physocarpus) • Oakleaf Hydrangea • Pearlbush • Pyracantha • Quince • Thunberg Spirea • Vanhoutte Spirea • Weigela • Winter Daphne • Witch hazel PRUNE BEFORE SPRING GROWTH BEGINS: • Abelia • Anthony Waterer Spirea • Beautyberry (Callicarpa) • Bluebeard Shrub (Caryopteris) • Butterfly Bush (Buddleia) • Camellia • Chaste Tree (Vitex) • Cranberry bush Viburnum • Crape Myrtle • Floribunda Roses • Fragrant Tea Olive (Osmanthus) • Grandiflora Roses • Japanese Barberry • Japanese Spirea • Mimosa • Nandina • Oleander • Panicle Hydrangea • Potentilla • Red twig Dogwood • Rose-of-Sharon (Althea) • Summersweet (Clethra) • Sweetshrub/Carolina allspice (Calycanthus) • St. John’s Wort (Hypericum) Once you have a basic understanding of when and how to prune the shrubs in your landscape, the task becomes a breeze and your plants will appreciate the attention!