How to Prune Your Boxwoods

Luke Gustafson, Agent Associate for UME Charles County shows how and why you should prune your boxwood to keep them healthy and disease-free.

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Boxwood is a common landscape plant in Maryland and it's important first of all, to go through and removed any dead, damaged or diseased branches. You want to get that out. You want to prevent that any disease from spreading to your healthy boxwood. Second of all, thinning pruning improves the air flow through the shrub and that reduces the likelihood for disease and also increases the light coming into the boxwood. Pruning stimulates new growth. Every where you have a cut, you have the buds below that pushing out new green growth. Pruning is also essential to restrict the size. If you inherited boxwood, maybe you moved into a new place and you have overgrown boxwood, you can slowly over time bring those down to a manageable size. When pruning boxwood, you want to follow the one third rule and not remove any more than one third of the plant at a time.

And this is to keep from shocking the plant. And also having just excessive new growth. Here's some great tools for pruning boxwood. The first one I have here is a bypass sheers or pruning shears. And this is what I use to make the majority of the pruning cuts. This can handle cuts up to about a half an inch and it can fit into those tight spaces. For larger cuts, I mostly use a folding hand saw. I can reach into the tight crevices. So anything that's larger than about half an inch, I switched to a saw like this. Lopping sheers are another option for making those larger cuts. Most lopping sheers can handle cuts up to an inch or an inch and a half. With all these pruning tools, it's important to make sure that they're sharp. This will save you frustration in the garden. It'll make it safer. And also sharp tools make cleaner cuts, which heal faster. Let's get to pruning this boxwood shrub.

I like to start by removing the dead from the interior of the shrub. We can see here some small dead branches. This is about the thickness of a pencil lead for that kind of small stuff. We can just snap it off with our hand. Now for the larger branches, we can come in and and use pruners and clean that out. Next I'm going to do a combination of thinning and pruning cuts. So anywhere that I see this really hairy growth that's up above the shrub, I can just follow that back down rather than just nipping it off there. I can make a thinning cut out of it as well. I can follow that back down even into the interior of the shrub.

And there you go. You're shaping it and you're thinning it at the same time. You don't want to leave a big gap. So I just kind of fluff the shrub every so often to make sure I'm not leaving a big hole. Some, some of the cuts I'll make will be smaller. I'll take this. You can feel there's a lot of stiff, woody growth here. A lot of stiffness to the shrub, so I'll take that back down. So now that I've made a number of thinning cuts, I'm going to do some final shaping cuts. What I'd like to do is take a couple steps back and look at the general shape of the shrub, and then see where I need to make those final cuts. So here's our finished pruned boxwood. It was pretty straight forward, and now we've got a happier, healthier shrub.