None of my Astilbes (False Spirea, Goatsbeard) bloomed this year. For those which did put out flower buds (or whatever is the correct term for immature inflorescence), the buds kept drooping, turned brown and never ever bloomed. The edges of the leaves are brown and the leaves curling (as if the plant is subject to drought or excessive heat). I know the roots have to be kept moist and require more water than other plants.
Also, I planted about 8 new Astilbe plants (from Breck's, in April) and only about half of those put out new leaves, much less blooms.
Two possible causes: 1. I dug out the bed around the existing plants, mixed in compost into the dug soil and put it back in the bed. I may have disturbed the roots. I know the Shasta Daisys did not like that, but still some flowered this year.
2. I sprayed the roses with Neem oil spray this year for the first time. There might have been some overspray that hit the astilbes. I hope they are not reacting adversely to the Neem oil.
The Astilbe which I missed this year the most is the three-year old white Deutschland. The smaller four-year old Chinese pink has never really done well.
I did fertilize the Astilbes along with all the other plants on July 4th, hoping that some will survive.
Would you happen to have any ideas why Astilbes are not doing well this year? Any suggestions on ensuring their survival and bloom for next year?