18. Astilbe
Shade plants are already tough enough to come by, but even more so for those that flower. Astilbe, thankfully, comes in to save the day as a shade flower with incredibly lovely, delicate foliage and amazingly showy, dense clusters of flowers that almost look like an old feather duster.
The large, showstopper flower heads range from pure white to dark purple with many shades in between, including gorgeous vivid pinks and deep reds. They are an absolute must for any shade garden.