Taking some radical pruning steps in 2011 will bring many of your large hedge rows back into shape. Beginning in the spring, reducing many of your overgrown hedges by as much as 80% will not only begin the process of returning them to a manageable size and their intended beauty, but save you hours of maintenance costs.
Shrubs can be cut back in spring to take them down to a more manageable height, help to rejuvenate them, increase flowering and remove winter damage. It is best to prune before significant growth has occurred and hot weather begins, as this weather can stress the plants. The earlier this can be done the better it is for the plant material, with the exception of flowering shrubs. To cut them back before they flower will remove all or most of the flowering potential. These spring flowering plants, such as Forsythia and Azalea, are best pruned after they flower. For a healthy plant, re-growth will occur fairly quickly, often within the initial growing season. Depending upon the shrub and the amount pruned off, you can expect it to take 1-3 years for the plant to fully recover to its intended but more manageable shape. Euonymus and other fast-growing plants will usually recover that season. Taxus sp. (Yews), Ilex sp. (Japanese Holly), Boxwood and other slower-growing plants may need an additional year to fully recover depending upon factors such as plant health, how much was cut off and growing conditions (sun, shade, irrigation, drought etc.).
Renovation pruning is necessary on older or overgrown shrubs that have outgrown their given area. This type of pruning is also normally done in the dormant season when the plants are not actively growing (before the new growth breaks out in the spring). This often requires a plant to be pruned back more severely than when regularly pruned. The rejuvenation pruning will stimulate new growth and will eventually increase flowering and improve the overall appearance of the plant. Overgrown shrubs, such as plants that are encroaching on sidewalks, covering memorials, stones or other plants, or covering windows, can be brought back to scale and increase the visibility and safety of a site.
Practically all pruned plants will re-grow quickly in the spring and early summer and will not show any detrimental effects from this type of pruning within a few months, with many having improved by more closely assuming their natural appearance. However, there are some plants that may not take well to radical pruning, e.g. Juniper that have a “dead zone” and many of the Rhododendron species that may not come back the way you might expect. That does not mean they should not be pruned, it just requires a more gentle hand.
Rejuvenation pruning is an essential part of a healthy landscape pruning schedule. Coupled with skillful summer pruning, it will allow plants to attain their greatest ornamental value, reduce pests, keep them in scale with the surrounding landscape and reduce overall maintenance costs.