The best time for major pruning of non-flowering evergreen shrubs is spring, after the threat of frost has passed.
But like many gardeners, Martha likes to clean and shape her shrubs in the summer, when shrub growth is most active. (Don't wait too late in the summer, since the new leaves won't have time to ''harden off'' before the onset of cold weather.)
Which tool you use for pruning depends on the type of look you want your shrubs to take. For a more natural and rounded look, Martha prefers shaping with handheld pruners and shears as opposed to electric hedge clippers, which create a more uniform effect.
1. Lay down a drop cloth and some baskets to catch trimmings.
2. Remove any dead, damaged, or diseased branches, as well as any new growth that stands out or is too long or bushy, being careful not to cut too drastically.
3. Stand back every now and again to check the shape of the bush. Gently shake the bush to help dislodge any debris.
Boxwood Planting Tip
If you decide to cultivate boxwood, buy a fairly small plant so that you can begin shaping it early. Do not plant the bush too closely to other plantings -- they need room to grow. Boxwoods (Buxus), hardy from Zones 5 or 6 to 8 (some cultivars are hardy to Zone 4), will thrive in either sun or shade and like moist soil with adequate drainage.
Too much moisture makes them prone to developing root rot, a disease that causes patches of yellowing or off -- color foliage. If you see this, try to improve your soil's drainage by adding coarse sand or organic matter, such as compost or manure, or transplant the boxwood to a location with sharp drainage.