Your buxus may be going brown due to environmental conditions or to disease. Taking a close look at the plant helps you figure out what the problem is and how to fix it. One reason that is becoming more common is box blight but more on that further down. I’ll start with the less serious problems.

If you have them in pots, the first thing to check is that there getting enough water and if they are, they are not getting too much water which is equally as bad if not worst. Both under and over-watering can cause buxus to turn brown. Check potted buxus have holes in the bottom of the pot so water can drain freely as this is probably the most common reason buxus turn brown as they literally drown.

Not water related! check out the other reasons below:

Sunburn (leaf scorch)

If the colour on your buxus leaves has faded all over and the leaves have what looks like brown burn marks on them, then your plant is receiving too much direct sunlight. Your buxus has leaf scorch, which is the plant equivalent of our sunburn. This is more common on fresh, young growth.

What to do

If your buxus is in a pot, move it to an area that’s more shaded or receives fewer hours of direct sunlight. If the plant is in the ground, rig up a screen for it, perhaps a wooden panel or a canvas sail.

And there’s an argument for leaving pruning until later in the year when the new foliage has hardened off a bit. When you’re pruning, make sure the newer leaves have some shade protection from older, larger branches.

Really, this problem is more about planting it in a more suitable position. You can learn more about planting and caring for box plants here

Frost will burn new growth turning it brown

New growth in a buxus plant is the most vulnerable foliage. It’s susceptible to any frost that occurs in the spring when the new shoots first appear. If they’re hit by frost, the smaller leaves may turn brown.

What to do

If your buxus plant is in a pot, move it to a sheltered location if there’s any threat of frost. Place it by a wall or in the corner of your patio or front porch. For plants that are in the ground, consider covering them up with hessian or horticultural fleece. Once the risk of frost has passed you could lightly prune the damaged new growth. This is common if we have a long periods of mild weather in spring followed by a late sharp frost.

If you have yellow leaves on your buxus, then this guide might be more suitable for you.

Box blight (the more serious cause of brown leaves)

Box blight is a fungal disease that leaves rust-like blisters or blotches on the leaves of a buxus plant. If develops mostly in autumn or winter and affects new leaves. The blotches continue to grow bigger and thicker and look browner. The leaves turn brown and often fall from the plant, leaving some bare patches.

What to do

Check on the underside of the leaves. If your plant has box blight you’ll see masses of white spores, especially if it’s wet weather.

Increase the air circulation through the plant. This is a matter of delicately balancing the amount of pruning you do. You need to prune enough to let the air flow through but not prune too much to encourage new growth.

Remove all the fallen leaves and the infected ones still on the plant. Cut back any diseased branches.

Spray the tree with a fungicide to discourage any more of the disease from moving in, though this is not guaranteed.

Feed the plant with a general purpose balanced fertiliser to help it recover. In badly infected plants, it may not recover, and you may need to dispose of it.

If you have brown leaves on your buxus, then this guide might be more suitable for you.

I have a dedicated guide on reviving dying buxus which you can read here

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