Saving Water Lilies After Ronstar Herbicide Exposure

Ronstar (pre-emergent herbicide) drifted onto water lilies, causing leaves and flowers to rot. The owner fears total loss and asks if the pond must be drained.

Good News: Roots Likely Survive

Ronstar damages contacted foliage but rarely kills the rhizome. The plant can regenerate from the crown if damaged parts are removed promptly.

Rescue Steps

1. Remove all brown/rotting leaves and stems: Cut back to healthy white tissue.
2. Do not leave decaying matter: It consumes plant energy and pollutes water.
3. If severe: Lift the plant, trim all foliage, wrap rhizome in damp newspaper in a black bag, store cool/dark (garage) until next spring.
4. Replant in spring: Fertilize heavily at planting.

Prevention

Never apply granular herbicides near water on windy days. Use a shielded sprayer for spot treatments. Consider a vegetative buffer strip.