I agree that something's wrong..I've seen nematode pics that look like the "brown line"..is every leaf like this?..interested to hear what the others say..

It does look nematode-ish. If that's the only bad leaf, I'd cut it off, seal it in a plastic bag and throw it out.

Unless you see more of it I would not worry about it. Some form of environmental damage to the leaf

Yes, I think it's too early too... usually in the fall. I had similar marking on one hosta (a leaf or two) a year or two ago - I chalked it up to sunburn/weather as the plant has been fine since then.... more than fine - Lakeside Cupcake is growing beautifully. This also appeared on my Cherry Berry one summer when we rushed from winter to summer-like temps and almost missed spring...similar to this year.

Okay, I’ll take a deep breath and just keep an eye on it. That was the only leaf like that and it’s gone with the trash.

We definitely have had weather like you described Jo - winter to summer almost overnight.

I was especially bummed yesterday when I saw that because this plant is finally starting to settle in and look like something:

I'm glad that the problem affected only one leaf..now that you've removed it I hope that takes care of it..

does it go vein to vein???

it doesnt seem to???

Hmmm. Ken- now I wish I hadn’t been so quick to throw it away. Maybe it didn’t quite go vein to vein.... but not sure.