Troubleshooting Yellowing Daylily Foliage and Poor Blooming: Water, Fertilizer, and Rust

Yellowing Daylilies: Common Causes and Cures

When daylily foliage turns yellow and blooms are sparse despite full sun, the issue is usually cultural or a fungal disease called daylily rust.

Check Watering and Drainage

Daylilies need consistent moisture but hate soggy soil. Both drought and waterlogging cause yellowing. Ensure the bed drains well and water deeply once a week if rainfall is lacking.

Fertilizer Caution

Too much fertilizer, especially high-nitrogen types, leads to lush leaves but few flowers. Do not apply bone meal or any fertilizer now. A light application of balanced fertilizer in early spring is sufficient.

Daylily Rust

Look for orange-brown pustules on the undersides of leaves. If present, remove and destroy infected foliage. Improve air circulation by dividing crowded clumps. For photos and details, see the Cornell University fact sheet: Daylily Rust.

Addressing these factors should restore healthy green foliage and abundant blooms.