If they were newly planted last year and the winter was dry, they probably needed extra water. Cold, dry winters can be deadly to new plants. Same thing, with mild, dry winters. Did you put down a good layer of mulch to protect the roots from the cold during winter? That will help next time. It could also be that a vole or something ate the roots or damaged the branches over the winter. Another thought, did you fertilize late in the season? Encouraging new growth late in the fall can be deadly too. The new growth doesn’t have a chance to harden off before the temperatures drop and the plant struggles. I hope this helps you rule out some possibilities and figure out what happened. Our planting and care guide has good ideas for getting plants off to a good start and keeping them healthy.
Thanks for writing!