So lovely to be able to maintain that NOID for such a long time, Lilli. Looks great and seems like an excellent site selection for a perennial planting. 30 years is quite a long time.
Of course growing conditions differ, but there seems to be quite a difference in how quickly crown imperials clump up. Most, but not all of the ones I have here divide very freely. My first crown imperial, 'Aurora', which I no longer grow, in fact divided so freely that it never reached flowering size. I tried to leave it in ground and I tried summer baking and it always refused to bloom. Yet it grows perfectly fine in many gardens. I'm very happy I didn't stop there, but tried other cultivars.
