|My astilbe are getting rather large but I do not know exactly how or when to divide them. Do I cut the foliage back before I start and how large a piece should they be divided into.
|Divide astilbe just as new growth begins in the spring. Amend the planting holes with compost and perhaps a slow-release fertilizer. Astilbe does best if divided every 3-4 years. It should spread fairly quickly, so you can start with small divisions.|