How To Shape A Boxwood Shrub
If you've just moved into a new home, you may find yourself with boxwood shrubs to deal with. English boxwood is one of the most commonly used shrubs in gardens using a more formal layout, but it can add a sense of structure to casual landscapes as well. Boxwood can work well in several planting zones (including zones 5-8) and can reach 15 feet in width and 20 feet in height. It grows quite slowly, which means that it only takes a bit of shaping and pruning to accomplish a lot.
Step 1. In the early spring or late winter, use your hands to part the boxwood to determine the depth of the green growth. Because of how dense boxwood is, the inside of the plant usually dies. This means that there is only an outer shell of a few inches to 1 foot that actually grows.
Step 2. Look for where the outer growth joins onto a branch. Use bypass pruners to remove pieces that are no longer than the plant's active growth width (the "few inches to 1 foot" referred to above).
Step 3. With the older branches, try to focus on any that are sticking out of the rounded shaped boxwood. You want to remove about one-third of these branches. Since you are thinning it out, you want to make sure that you distribute these cuts evenly around the plant from every angle. By doing this, you will let more light and air into the plant to encourage growth and reduce the chance of disease. This will also help to reduce the overall size of the boxwood while still maintaining its shape.
Step 4. Use shears to cut back the exterior of the boxwood to produce a formal looking appearance when the new growth is starting to harden off (becoming a darker green) during Midsummer. Make sure you leave behind at least 1 inch of the new growth. However, in some areas you will want to leave more than 1 inch in order to get the shape you're trying to achieve. While hedge trimmers will allow you to do this more quickly when you're dealing with a lot of boxwoods, if you want to ensure your control over the result you should use hand shears.
Step 5. Be sure that you shape the boxwood to make it slightly narrower at the top and wider at the bottom. This will guarantee that the entire plant will receive a sufficient amount of light.