Improve plant health with dormant pruning

Burrrr.... who would venture into the cold and snowy weather this time of year to work in the yard? The brave souls that don their long johns, scarves and parkas to do some dormant pruning will be rewarded with healthier landscape plants and less work in the long run. Many people fear damaging plants and avoid pruning all together, but with a little knowledge and practice, anyone can achieve positive results.

Pruning is the removal of plant parts to improve plant health. You should remove dead, diseased or damaged plant material at any time. And, there is no time like the present.

Let's start with the basics

Dormant pruning is comprised of three parts. Corrective pruning redirects growth to achieve a desired shape and a more natural-looking plant. Preventive pruning removes dead, diseased or damaged plant material, as well as problematic branches that may hang over walkways or grow into buildings and homes. Rejuvenating pruning cuts back heavy growth and thins crowded older plants to encourage new growth.

Dormant pruning benefits ornamental plants and trees by removing unhealthy or excessive growth and deadwood, and by improving the natural branching characteristics of the plant. The best time to do it is late January through early March when the plant is inactive. So grab your hat, gloves, and tools and let’s get busy.

Dormant pruning helps to maintain a plant’s size in a limited space, and it revitalizes older, woody plants. A plant pruned during dormancy becomes healthier in spring as the plant's energy is directed to its fewer remaining branches supported by the same root mass, resulting in a more prolific and healthy plant. Dormant pruning also reduces headaches during summer pruning work. Keep in mind that pruning actually encourages growth. For those plants that are sheared in summer months like the common privet hedge, new growth rapidly appears at twice the growth output. This is what causes the outer portion of the plant to become so woody – and darn tough to cut back after years of shearing. Selectively removing some of the excessive woodiness will help to redirect plant growth, enabling the plant to fill in its bare areas.

How to prune:

Before you start, have a vision for what you will accomplish so that you are careful to prune in the correct way to achieve your goals. Determine what the plant can handle (you must know the plant you're working on and its growing habits). Some plants need to be pruned gingerly, while others benefit from a vigorous pruning. In general, it is best not to prune more than a third or a quarter of any ornamental or tree, and in many cases, removing a fifth of the plant is more appropriate. Rejuvenating pruning usually involves a three to five year pruning plan.

When you are ready to prune, follow these steps in order: 1) remove dead, diseased and damaged wood from the plant; 2) clear building structures, paths and driveways of obstructing plants; 3) remove any crossing or rubbing branches that might cause future injury; and 4) thin and cut back according to the plant’s natural growing characteristics. Thinning prevents ornamentals from becoming top heavy and more susceptible to winter snow damage and it encourages the plant to fill in the lower areas with new growth.

Avoid pruning in late fall or early winter. Soil temperatures are still warm and the plant is still actively transferring its energy stored in the canopy to the root system. Pruning in late fall robs the plant of this vital stored energy, potentially weakening it. Heavy fall pruning is not advised because it may encourage new growth that may not have time to harden off before cold weather sets in, potentially causing frost damage to the new growth. One major exception to late winter pruning is spring-flowering ornamentals (e.g. lilac, forsythia, viburnum), which are best pruned after they flower and before they form flower buds for the following year.

To learn more e-mail info@lawnlad.com and receive a free copy of Pruning Landscape Plants, OSU Cooperative Extension Service Bulletin #543.

Douglas Freer is a Cleveland Heights native and is the owner of Lawn Lad, Inc. Lawn Lad provides residential landscape services in the Heights area. Call 216-371-1935 or visit www.lawnlad.com.