They need a good watering system in summer, and a light pruning in the middle of march, when there is no more danger of frost. Never in the fall! Once every three years, I cut them back more harshly. Most of them have been planted about ten years ago. A partly shady area is better for their growth. Some were pink when I bought them, but since the soil is acid in British Columbia, the gradually became blue. Actually I much prefer them blue. I think they are more spectacular! Hope this will help!

Thanks a bunch! I'm fairly new to gardening and I'm learning when and how to prune.

wow.... thank you so much.... I just love them!!