I 'chop' my Sedums, to stop them flopping, and some stems of phlox (so they flower for longer).

Hi Andy, I 'chop' some Sedum so that they flower a bit later, others I leave, so the flowering period is extended, the rest of my perennials are still quite young, so I don't bother with them, but I may do as they get larger, Derek.

I've never chopped because the growing season is so much shorter in Scotland. Maybe I'll try it one day!

I chop some of my tall white daisies and some michaelmas daisies because their growth hides other things which flower earlier. It works well.

I chop my heleniums and they are much better for it.

I have sometimes chopped my sedums and solidago, but I feel that - although it makes them a bit tidier - it delays flowering to the point where the bees and butterflies don't get the maximum benefit. As that is my main reason for growing them in the first place, I tend not to chop.