Do you have boxwoods, cherry laurels, or other shrubs with evergreen leaves in your yard or landscape? Late winter and early spring are the best times to prune these and many other leafy evergreens in your landscape.
Aucuba (Aucuba japonica), boxwood (Buxus sempervirens), cherry laurel (Prunus laurocerasus), and osmanthus (Osmanthus sp.) are a few of the many shrubs grown for their evergreen foliage rather than their blooms or fruit. Often serving as foundation plants and hedges, such shrubs have a variety of leaf shapes and leaf variegation (different colors in the same leaf) that make them welcome in the winter landscape.
Do you need to prune?
Although the title of this blog post is “Pruning of Evergreen Shrubs,” of all the plants in your landscape, evergreen shrubs require very little annual pruning! They grow into desirable forms by themselves and only need an occasional helping hand from you. When you do prune, keep the following in mind:
- Always carry a sharp pair of hand pruners in your hand or a leather scabbard on your belt when working with the evergreen shrubs in the yard.
- Be on the lookout for dead or broken branches and remove them promptly.
- Remove any branches that are crossing over each other as they can rub the bark and make the plants more susceptible to infection.
- Prune back branches that are growing onto driveways, sidewalks, and patios. When pruning, be sure to cut back to a branch or node that is pointing in the direction that you want it to grow.
- When you shear hedges, remember to leave the bottom of the plants a bit wider than the tops to get light to the lower limbs, keeping them lush and green.
- Prolonged use of electric hedge shears will result in a very small veneer of leaves just on the outer surface of the plants. If part of a continually sheared plant dies, the inner leaf buds will not develop and you will be left with a “hole” in your hedge. Take a look inside your hedge, and if you do not see leaf growth along the inner branches, you need to seriously consider using hand pruners to thin out portions of the plant canopy so light gets into these inner areas and the secondary buds have a chance to develop.
Some of these plants (such as boxwood or Japanese holly) can be pruned into fantastical shapes in topiary form. Plants shaped this way bring to mind animals, ships, and buildings. Forming plants into topiaries requires a tremendous amount of time and pruning effort to maintain their shape—almost constantly pruning off the stray branch or leaf—but the reward is a uniquely personal landscape.
Evergreen shrubs are relatively disease- and insect-free and can be remarkably winter hardy. The fact that these plants keep their broad leaves throughout the winter, however, makes them particularly susceptible to winter desiccation and damage. You can avoid this by choosing the correct varieties for our area—pay strict attention to the hardiness zone when purchasing shrubs. Western North Carolina is generally in the USDA Hardiness Zone 6 or 7. Keeping a layer of mulch around the base of these plants will help to conserve moisture and minimize winter damage.
Caution! Know your shrubs!
Now is NOT the time to prune evergreen shrubs that you grow for their flowers! If you are uncertain, the Extension Master Gardener volunteers of Buncombe County can help you identify the plants in your landscape.
- In general, shrubs blooming before June bloom on old season’s growth and you should prune them directly after blooming. Examples of plants in this category include azaleas and rhododendrons (both are Rhododendron spp.), as well as Japanese camellias (Camellia japonica) and mountain laurel (Kalmia latifolia). We will discuss their care in a future blog post.
- Shrubs that bloom later in summer—such as hollies (Ilex spp.) and Pieris spp. (commonly known as andromedas or fetterbushes)—bloom on new growth so you can prune them before growth begins in the spring.
Article written by Bob Wardwell, Extension Master GardenerSM Volunteer.
The Art and Science of Pruning
by N. Jordan Franklin, Consumer Horticulture Agent
Clemson Cooperative Extension
Pruning Trees & Shrubs: General Pruning Techniques
by Barbara Fair, Lucy Bradley, and Anthony LeBude
NC State Extension Publications