Troubleshooting
Narrow-leaved Watsonia problems — and how to fix them
Narrow-leaved Watsonia (Watsonia angusta) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Corm rot in winter
The main risk in cold, wet climates. In USDA zones 7 and below, lift corms in autumn, dry thoroughly, and store frost-free.
Thrips
Similar to gladiolus; thrips rasp flowers and leaves causing silvery streaking. Treat with pyrethrin spray or neem oil.
Invasive spreading in warm climates
Watsonia is listed as invasive in parts of Australia and Hawaii. Deadhead before seed sets and avoid planting near natural areas in warm, frost-free regions.
Failure to flower after a cold winter
In marginal hardiness zones, corms may need a warm, sunny position with good drainage and a generous mulch to survive and flower the following year.
Prevent narrow-leaved watsonia problems before they start
Most narrow-leaved watsonia issues are care-mismatch, not bad luck. Dial in the basics:
Narrow-leaved Watsonia problems — FAQ
Why is my narrow-leaved watsonia corm rot in winter?
The main risk in cold, wet climates. In USDA zones 7 and below, lift corms in autumn, dry thoroughly, and store frost-free.
Why is my narrow-leaved watsonia thrips?
Similar to gladiolus; thrips rasp flowers and leaves causing silvery streaking. Treat with pyrethrin spray or neem oil.
Why is my narrow-leaved watsonia invasive spreading in warm climates?
Watsonia is listed as invasive in parts of Australia and Hawaii. Deadhead before seed sets and avoid planting near natural areas in warm, frost-free regions.
Why is my narrow-leaved watsonia failure to flower after a cold winter?
In marginal hardiness zones, corms may need a warm, sunny position with good drainage and a generous mulch to survive and flower the following year.