mine are all proud of the waterline. They grow like this in the wild so i dont worry about it. If the clump gets too big split them and replant. they are a lovely native iris.

Thankyou, SBG. That's reassuring. And I don't need to do anything, which is even better.

yep let mother nature do her own thing :o)

there quit a thug infact given the opertunity and can easily take over .

Thanks, NP. I won't be letting them spread too much, just a wee bit more than they have at the moment to fill out a horrid wet corner. (Long story, small spring, just outside my boundary fence on public verge, no obvious cure except to plant bog plants that like it. All happy.)

great idea with a nice splash of colour .