I posted a photo in the Garden Clinic forum...

Here is a link that might be useful:

looks like how the leaves get later in the summer when they start to get dried out. I bet it is just transplant stress.

that makes sense. i will have to see what happens next year when they come back up. i don't plan on moving them again.

thanks!

I'm far from an expert, but I've had Lily-of-the-valley at three different homes during my lifetime and for 30 years they've always gotten those dry cracks once the heat of summer arrives. I was actually going to post a question whether it is OK to cut back the leaves once they start to get dry like that. I assume, though, that the plants need to maximize their photosynthesis over the summer to store energy in the rhizomes (I think that is what LOTV have). Maybe with a regimented watering schedule you could keep them from getting so dry. But, my suspicion is that this is a normal part of their life-cycle.

I agree with docmom. My lily-of-the-valley do the same thing.

Right, the only time I didn't have that problem was when I planted them under a water faucet.