I"ve got the same thing here in okc, all the bottom leaves are yellowing. I signed it off to a rainy wet spring cause I know my soil has to be all right...

however, the weird thing is I like to keep them watered every couple of days, but the yellow leaves confuse me as them having too much water but after 4 days of no rain???

there's my 2 cents

I would be a bit concerned about the possibility of crown rot. If I see the new growth showing signs of yellowing before the older leaves I usually will suspect crown rot as being the cause. More so if we have had a long run of very wet weather and the soll is heavier and wetter than usual. In the garden here I've found it to be more of a problem with newer plants that haven't established themselves yet....I've VERY rarely had an older more established plant develop crown rot issues. I would probably lift one of the more yellow lilies and look to see if you have an abundance of rotten roots or bad smelling decomposition around the crown area of the plant. If you do you will have to thoroughly clean away the rot and either move or pot the plant/plants so that they have a chance to recover, and limit watering until you see signs of healthy new growth.

Linda

I agree with Linda - I've seen it happen here. If more than just the very bottom leaves are turning yellow, it could be a forerunner of a plant dying from crown rot. Since I've been using Kphite, I haven't lost any more. You might want to do some research on it.

Nancy

on my plants it's only; the bottom outside leaves that are yellowing only. I think I'm going to raise them all higher up this fall, seems like the mulch and stuff might be a bit deep around them.....

Thanks everyone. I have pulled some yellow ones from the middle. I think I will lift the worst offender and take a look.

I knew you all would have some ideas......thanks again.

Will also research the suggestion of using Kphite.