Hello, and thank you for contacting us about your shrub. From the photo, it appears to be a type of ornamental juniper, perhaps 'Blue Star'. 

Junipers are not particularly well-adapted to our soils and climate. There are a number of reasons the foliage is turning brown, especially when junipers are grown in heavy clay, waterlogged soils, or are heavily mulched such as with black plastic. Poor drainage alone can create root problems that cause dieback.  

Junipers are adapted to dry, barren, rocky or sandy soils (which provide excellent drainage and aeration) and full sun. Check whether your shrub has the desired growing conditions, as this may be the problem. Also, make sure mulch is not placed directly on the crown of the shrub.

Junipers need good airflow to avoid fungal disorders, so pruning out any dead wood is important. Clean pruning shears with 10 percent bleach solution or rubbing alcohol between every cut. 

It is also important to keep branches dry during warmer weather. Avoid overhead watering, especially in the evenings and during warmer weather. 

Check for aphids or caterpillars which may have infested the plant. Also, look for spider mites: Hold a piece of white paper under a branch and shaking it. Use a magnifying glass to examine any small specks that fall on the paper. If you see brown, red, green or yellow eight-legged insects, your juniper has spider mites.

I wish I could give you a definite course of action, but right now we don't have enough information to determine the cause. See what you can find on closer inspection, and reply to this email with a description so we can try to advise you.

Best Regards,

Thank you for the information and your time!

Gail