Now that old man winter has descended upon us, as gardeners, we are looking for projects to get us out of the house. It is the perfect time to renovate that old boxwood (Buxus) hedge. Fellow gardener, Nicole Selby, and I performed this rejuvenation on an aging boxwood hedge last month.
This particular hedge is informal in style. Due its informal style, regular yearly pruning to maintain its shape is not necessary. However, over time informal hedges can begin to look tired and leggy. When this happens a significant renovation to restore its youthful charm becomes essential.
Luckily Buxus along with Cephalotaxus, Cryptomeria, Cunninghamia, Ilex, Sequoia, Taxus, and Torreya respond well to hard pruning and will regrow from older wood. As a result, large pruning cuts made on old wood are perfectly acceptable.
Renovation pruning should be performed every 5 years or less to prevent large woody trunks. Frequent renovation will also eliminate such dramatic transformations as seen in these images.
Before making your first pruning cut, decide what the ideal final height of the hedge will be after a few years. Boxwood are typically slow growing so once you have established a desired height, perform your pruning cuts 6 inches below that desired final height. This allows for several years of maintenance-free growth.
Boxwood will regrow from bare old wood but it will take longer to bounce back. Ideally pruning cuts should be made in a location where there is active growth. While performing the renovation, it is an ideal time to remove any dead, damaged, or diseased branches.
When a dramatic renovation is needed, it is best to stagger large cuts over several years. Remove one third to one half of the large branches yearly over a two or three year period. This allows the plant to build up reserves and recover throughout the renovation process.
Mulching and fertilization is recommended after pruning; by doing so you will help the hedge regain its youthful glow in a timely manner. Happy pruning!