Boxwoods are notorious at browning out like that. My mother has a 40 year old one that has done that on and off over the years and she just prunes it out (and actually uses the pruning as an arrangement in the house). There are apparently several possibilities including a stem blight caused by a specific fungus and the result is often seen after winter (which itself seems to hasten the problem) where a whole branch will die back. Alternately, if that area of the plant is exposed, it could be latent winter damage.

This was my mother's a few years ago and you can see the open "hole" where a browned-out branch was removed. The spots that have been hit are generally exposed (the exposed portions face south):

{{gwi:247351}}

Thanks, I'll try to just prune the bad stuff and see if it can recover. I did start to prune the bad stuff off and I noticed the branches are still alive. That's when I decided I better check here first. =)

Once that section is removed, light and air will be able enter into that open area and it should start to gradually fill in during the next couple years until you won't even know that it was removed. Good luck!

Mine are like that and one died completely this winter but I think it is likely because my husband shovelled the snow onto them and it may have had traces of salt from the walkway. I clipped out the worst parts and am glad to hear they will renew themselves. Probably not the best for my Zone 5 area, but I love the look of them!

Well, the final picture shows some nasty lesions at the base of the stems. If you're going to remove the dead stems,go as far down as possible, then cross your fingers for the rest of the shrub.

Around here the things get a root rot. To check yours -- before or after you remove that affected stem, scrape off the bark at the base. If it's Phytophthora root rot, you'll see a cinnamon-brown color (usually within two inches of the base), then a sharp demarcation to creamy white above.