Thanks, Janet, it's a good thought, but....I've tried a stone mulch on a bed
once, and it was a nightmare. Every possible weed and/or wild plant and/or
perennial seed around found its way there, germinated, and dug in. It was
harder to weed than a mulched bed, so I ended up removing the stones (such a
pain) and switching back to bark mulch.

I understand that irises like to have their roots rhizomes dry and baked.
The thin layer of mulch I use doesn't seem to interfere with that
requirement to any significant degree. The irises are in full sun, and near
the driveway, which probably reflects/retains heat and helps keep things
from being too soggy. If I had a problem with iris culture, I would explore
other options, or stop growing them, but my irises do just fine for me.
Someone else's situation may be different from mine; I'm just reporting on
my experiences, and saying it's ok to flaunt convention wisdom if you use
judgment and observation.

Cheers,
Sue

Zone 6, Southcentral PA




"Janet Baraclough" wrote in message
Have you thought of using grit or gravel? Most irises like a summer
baking and roots as dry as possible; gravel might provide thet better
than bark.

Janet.