Daylily Yellow Leaves in Heat/Rain: Drainage Is the Issue

Your daylilies have yellow/part-yellow leaves, no blooms yet. Lots of rain + 90°F. Otherwise healthy, pushing new leaves.

Diagnosis: Wet Feet

• Daylilies tolerate heat but hate soggy soil.
• Excess rain + poor drainage = root hypoxia → yellowing (chlorosis).
• New leaves = plant trying to compensate.

Fixes

• Improve drainage (raised beds, amend clay with grit/compost).
• Don't irrigate — rain is enough.
• Mulch to moderate soil temp/moisture.
• Wait — as soil dries, they'll green up and bloom.

Comparison

Expert's daylilies on a hill (drainage) = just starting to bloom, no yellowing. Yours in low spot = stressed.

It's the soil, not the heat. Fix drainage; flowers follow.