Organic Control of Columbine Leaf Miners and Caterpillars

A Minneapolis gardener with a 1000 sq ft perennial garden faces recurring leaf miners and green caterpillars devouring columbine leaves. They prefer organic methods and have tried removing infested leaves.

Integrated Organic Strategy

Jack DeAngelis recommends:

1. Garden renovation: Deep till (6+ inches) the entire bed before replanting to disrupt pest buildup from 10 years of accumulation.
2. Habitat for beneficials: Maintain a small (10x10 ft) unmanaged, weedy area nearby as a reservoir for natural predators and parasites.
3. Neem oil: Effective against chewing caterpillars. Apply per label. Neem oil info.
4. Spinosad: A natural microbial product highly effective on caterpillars. Spinosad details.

Rotate treatments to reduce resistance. Accept some damage; columbines often reseed vigorously.