It is my experience that some cultivars increase more rapidly than others and getting feedback from others in your climate helps you select. The older ones seem to be hardy and increase easily. Since the newer ones are expensive, I have only one or two of each and must be patient in hoping for clumps. Generally 3 years with no rot or pests will bring a nice clump. I am space-challenged in the suburbs so mine tend to be crowded anyway. I anvy those with farms and large fields but not when it comes to weeding and dividing.
