Mahonia dead?

I have two mahonia plants which have thrived for the past 15+ years, but this spring they show no signs of life. I notice other mahonias in the neighbourhood (downtown Toronto) which look similar. Have my plants not survived the…

Oregon grape, Mahonia aquifolium

I have this plant on the north side of the house where it gets very little light, but, grows happily. It has been there for years and years. Two questions. Each winter some ¬†upper branches die back and I prune…