One of my Astilbes, Vision in Pink, planted in front of some juniper shrubs, never did anything this year except to emerge and grow a few leaves. No flowers. My other Astilbe, an unknown red variety, grew 2 spikes of flowers which were more brown than red, right next to the first Astilbe. The soil is well-fertilized and kept moist, and there is sun there in the morning. Why did they perform so poorly?