I don’t mean to panic you, but RIGHT NOW (early spring) is the perfect time to prune your boxwoods. The weather’s fine, it’s too early to plant or even to weed – sharpen your Felcos and get out there!
Now there is pruning, and there is shearing. Shearing is removing an even length of growth all over the shrub, to give it a particular shape (like a round ball, or a flat-topped hedge). This is a formal look that is rarely suitable for suburban yards, and it’s a lot of work to maintain. Think thrice before you decide to shear.
When pruning, first clip out the branches that are dead or on their way out. There’s no point leaving them on because they won’t get any better and they’ll provide an avenue for pests and disease to enter the plant. Don’t mistake a coppery branch for a dead branch. Some boxwood, particularly when newly planted, can turn nearly orange in winter. Once the plants are established the color should be consistent.
After the deadwood is out, step back and figure out why you’re pruning. Mostly I prune to keep the bushes a reasonable size. Try as we might to fit the right plant to the right place, they do insist on overgrowing their spot…
Note that I am only talking about boxwood here. There are tons of other plants that could use pruning right now, and some of them should be approached differently because you may be pruning for better flower or fruit production, or to achieve a certain growth habit. But right now you’re pruning your boxwood, and you’re pruning for size because you have a big shaggy mess of boxwood squatting in the middle of your foundation bed.
So taking off the bad branches is the obvious and easiest thing to do. Next-most-obvious thing is to take off the branches that are brushing against your house, blocking a window or spilling over your walkway. Reach deep into the shrub and cut these out at an interior crotch (where another branch is spiking off). Deep cuts like this help air and light to find its way to the interior of your shrub.
The dead and diseased wood is gone. The out-of-control wood is gone. Next step, if you are pruning for size: find the longest sprigs, the ones that define the widest and tallest points. Reach in deep and cut these branches at an interior crotch. Go all around the shrub and keep checking it from various angles.
Now, clean up your debris and take a water break.
Come back and look at your shrub with fresh eyes. Find the little straggly sprigs and cut them back at a twig juncture. You should be making cuts of about 6 inches. Keep moving steadily over the shrub, reducing a bit and then reducing a bit more. You may find that you’re cutting the same twig twice – that’s okay – better to take it slow than to regret later. Keep in mind the overall form that you are trying to achieve. Depending on your cultivar, you may have a rounded shape, a vertical column, or even a pyramid. In all cases, please take care not to create a dramatically top-heavy shape that will create too much shade on the lower branches.
If you do accidentally cut more than you intended to, don’t worry! Next year’s new growth will fill in the gaps.
Are you looking for something boxwood-esque but more natural? You want inkberry or small leaf holly (Ilex glabra), which I will blog about later.