I wanted to add these pictures and note that I don’t see any visible pests after the neem treatments earlier in the summer. The leaves also largely stay on the branches if they turn brown. 

I wanted to add these pictures and note that I don’t see any visible pests after the neem treatments earlier in the summer. The leaves also largely stay on the branches if they turn brown. 

Thank you for contacting Ask Extension. After looking at the pictures that you sent, it seems like the boxwoods have Macrophoma Leaf Spot. The most obvious symptoms are the many tiny black raised fruiting bodies found on dying or dead straw-colored leaves. Also, the red-brown lesions on the leaves that are still green indicate that too. Pruning infected branches is sufficient management for this fungus. Also, thinning pruning is recommended to increase air circulation to help to reduce moisture. I have included a publication on how to prune boxwoods.

Also from your pictures, it does not appear that the planting height is an issue. But you should move the mulch back from the plant stem by about 3-4 inches. And the landscape fabric (I believe that is what the material sticking up from the mulch) should be removed. This can cause girdling in the shrubs and excess moisture to be held in the soil.

Here are some publications for your reference:

https://extension.umd.edu/resource/pruning-shrubs-and-hedges-home-garden/

https://extension.umd.edu/resource/boxwood-identify-and-manage-common-problems/

https://extension.psu.edu/boxwood-diseases

https://www.canr.msu.edu/news/browning-of-boxwood-is-it-boxwood-blight

Please contact us if needed for more help.

Thank you for contacting Ask Extension. After looking at the pictures that you sent, it seems like the boxwoods have Macrophoma Leaf Spot. The most obvious symptoms are the many tiny black raised fruiting bodies found on dying or dead straw-colored leaves. Also, the red-brown lesions on the leaves that are still green indicate that too. Pruning infected branches is sufficient management for this fungus. Also, thinning pruning is recommended to increase air circulation to help to reduce moisture. I have included a publication on how to prune boxwoods.

Also from your pictures, it does not appear that the planting height is an issue. But you should move the mulch back from the plant stem by about 3-4 inches. And the landscape fabric (I believe that is what the material sticking up from the mulch) should be removed. This can cause girdling in the shrubs and excess moisture to be held in the soil.

Here are some publications for your reference:

https://extension.umd.edu/resource/pruning-shrubs-and-hedges-home-garden/

https://extension.umd.edu/resource/boxwood-identify-and-manage-common-problems/

https://extension.psu.edu/boxwood-diseases

https://www.canr.msu.edu/news/browning-of-boxwood-is-it-boxwood-blight

Please contact us if needed for more help.