Troubleshooting
Common Toadflax problems — and how to fix them
Common Toadflax (Linaria vulgaris) is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Invasive spreading via rhizomes and seed
Spreads vigorously by creeping roots and self-seeds prolifically; deadhead promptly after flowering to reduce seed dispersal, and remove rhizome sections at the garden boundary annually.
Linaria antirrhinum moth (Calophasia lunula) caterpillar damage
The toadflax brocade moth (Calophasia lunula) is a specialist feeder that can heavily defoliate plants in southern England; hand-pick caterpillars or accept the damage as part of hosting specialist wildlife.
Prevent common toadflax problems before they start
Most common toadflax issues are care-mismatch, not bad luck. Dial in the basics:
Common Toadflax problems — FAQ
Why is my common toadflax invasive spreading via rhizomes and seed?
Spreads vigorously by creeping roots and self-seeds prolifically; deadhead promptly after flowering to reduce seed dispersal, and remove rhizome sections at the garden boundary annually.
Why is my common toadflax linaria antirrhinum moth (calophasia lunula) caterpillar damage?
The toadflax brocade moth (Calophasia lunula) is a specialist feeder that can heavily defoliate plants in southern England; hand-pick caterpillars or accept the damage as part of hosting specialist wildlife.