Q.astilbe plumes stunted
I have 2 purple astilbe plants in my front garden. I put in 3 years ago. The second year the plumes were tall and full. This year the color is beautiful but the plumes are much shorter, hardly taller than the greens of the plants. The green base is full and looks healthy. Our entire yard has large maple trees and this garden get partial sun. I usually leave the plumes even after they turn brown. Can I do something to encourage the plumes to be taller next year?