Iris x hollandica - 2020

Are they in a warm spot as reading about these on here the ones living in a warm zone seem to have lots of clumps even winter weather damage on the foliage can affect them. Seems even when you plant them it can affect their growth in cold climates. I have some by my path they have never doubled in a clump but then I damage the foliage with my chair

I read if iris feel over crowded they stop producing bulbs but it did nt say which kind of iris.

https://garden.org/thread/view/60687/Dutch-Iris---a-suggestion-to-improve-bloom-and-hardiness/

Yes, they are are in one of the warmest corners of the garden

So its not them getting enough warmth thank you for letting me know.