Fungicide Timing Critical: Prevention Beats Cure for Leaf Spot and Rust

Zone 8 Gardener's Failed Reactive Treatment

A gardener sprayed fungicide for 3 weeks on hydrangea leaf spots and daylily rust with no improvement, asks if more time or product change needed.

Fungicides Are Preventive, Not Curative

• Once spots appear, damage done – Fungicides protect uninfected tissue
• Change environment – Soaker hoses keep foliage dry
• Spring/fall low-nitrogen fertilizer – Plant strength
• Next year: preventive schedule – Spring emergence + every 10-14 days

Cultural management outperforms reactive spraying.