I purchased these daylilies at a local garden that sells their overflow. I left them potted for now. I plan to ground plant them later. They had blooms on them when purchased. They all bloomed and looked nice. The leaves are now turning yellow and brown. It looks like they are browning from the tips rather than the crown. Does anyone know what causes this? Are my new daylilies sick.

Pat I'm not an expert, but I asked on here for my DLs, the leaves were doing about the same, only not so brown. Someone pointed me at spider mites, so I checked with a magnyfying lense the back of each leaves, and I did find some; also they chew the leaves and you can see little brown spots. If they are many the leaves suffers and get brown. You could check your DLs for spider mites. They seem to like hot and dry conditions. HTH

It looks like leaf streak, see:

http://www.daylilies.org/ahs_d...
http://hyg.ipm.illinois.edu/ar...

If so, it's quite common in daylilies, and not always a significant problem. You certainly could check for pests because the leaf streak fungus is believed to need a wound of some kind (weather damage can do it too) to infect the plant. It's not unusual for some daylilies to get "ratty" looking leaves after they've finished flowering.

I'm not certain but in your top picture it looks like there could be leafminer damage, or is it a liquid of some kind that is running down the leaf? For comparison, see:

http://www.daylilies.org/ahs_d...

Pat - I think I get just about anything imaginable with my daylilies. Both disease and pests. I never lost any plants except the occasional dormant cultivars that I have tried to grow.

Check the AHS website daylily ailments. Just click on each underlined word(s) to find out more about each:

Pests:
http://www.daylilies.org/ahs_d...

Diseases:
http://www.daylilies.org/ahs_d...

Sue and I posted at the same time. I consider her the expert, so her advice is most likely on target!

Thanks guys...All of these plants have finished blooming, but they look so bad. I considered removing the damaged leaves but I wouldn't have much left. I would look over the links when I get home this afternoon and try to decide on a course of action.

Sue, in the first plant there is nothing running down the plant. We had a rain storm yesterday afternoon and I took the photos this morning while dew was still on the plants. They just look that bad.

Pat236 said:Sue, in the first plant there is nothing running down the plant. We had a rain storm yesterday afternoon and I took the photos this morning while dew was still on the plants. They just look that bad.

I've tried to mark, rather crudely using Paint, the areas I was thinking of with arrows. They look like they could be leaf mines but can't say for sure from the pic. It's the pale lines/areas not the leaf streaky looking yellow/brown bits.

Sue is wonderful. She goes above and beyond for so many of us. Thanks Sue! This thread may help me, too.

Sue, I see what you are talking about....they look like slug trails but I've never seen any slugs on these. What causes the little white lines? I've seen them on several of my daylilies. Sue you are the best!

It's a fly maggot that gets inside the leaves and munches its way along leaving empty trails as it feeds, called a leafminer (lots of different plants get them, but this one is specific to daylilies). It's a new daylily pest that somehow got here from Asia - if I recall correctly the first "sighting" in North America was as recently as 2006. Below is a link to more info. If you're squeamish about maggots don't look at this just before eating

http://www.daylilies.org/ahs_d...

Thanks Sue....this is exactly what I have. The article didn't say how to get rid of it. I will goggle leafminer when I get home.