By mistake, my husband moved way into my siberian iris bed. Will this kill them? Should I take it as an opportunity to divide and transplant them?

No, it won't kill them. Go ahead and divide, into larger pieces. My hubby's done this a few times.

I have mown my Siberians on a regular basis, just for the compost to put on a walkway or such. I am big on biodegradable mulch and composting, so if something is done for the season, I am likely to run the mower over it. I have mown my violets, walking onions, mint and daylilies too. Mint and onion mulch is lovely!

Whew! That's a relief!

Husbands..... gotta love 'em

If mowed too soon there might be fewer blooms the following season, at least with TB's based on a nearby house who mows immediately following blooms.

Yah -- they really need their leaves, as long as possible. But!! Mowing won't kill 'em.

with Mary Ann and Dave. While you won't kill your SIB's by mowing them, if you really want better growth and bloom you should avoid cutting the leaves down until fall.