Ferns & Astilbe are a perfect mix for the shade garden, creating a soft and colorful display. While ferns are initially expensive, they are a hardy perennial and multiply rapidly. They are easily separated to be transplanted in new beds or given to friends. They stay green all summer and die back to a stub in winter for easy fall or spring cleanup.
Astilbe and Ferns by Douglas Barnett
Fine Art America
For more berries, you should make sure to replace your entire bed after 3-5 years. Once the strawberry plants are older than five years, they start to decrease in productivity. By replacing your beds the younger plants will be able to take over and produce lots of new strawberries.