Question
I live on the west coast of British Columbia and last spring we planted a hedge of emerald cedars.  With the onset of spring, all of the shrubs are full of new growth on the tips of the branches.  However, some of the shrubs in different parts of the yard have spots of black near the bottom.  We wondered if this could be cat urine, as we have quite a few cats in the neighbourhood.  Can you advise?

Answer
L,
The problem with the cedars is not cat or dog urine, which would cause the foliage to turn yellow or tan, the problem is a disease called tar spot.
Tar spot is normally found attacking Norway Maples and cause no permanent damage to them, on Cedars however, this disease can be devastating.
I would recommend that you go to your local garden center and buy a fungicide that is labeled for this disease.
Good luck.
Ed Gulliksen