Troubleshooting
Waterfall Gladiolus problems — and how to fix them
Waterfall Gladiolus (Gladiolus cardinalis) 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 cold, wet ground
Not fully hardy in the UK or northern US climates. Lift corms after first frost, dry thoroughly, and store in cool, frost-free conditions over winter.
Thrips
Tiny insects cause silver streaking on foliage and distorted flowers. Use insecticidal soap or neem oil spray; destroy heavily infested plants.
Fusarium wilt (dry rot)
Corms rot from the base upward. Remove and destroy affected corms; avoid replanting in infected soil for several years.
Botrytis (grey mould)
Affects stems and flowers in wet conditions. Space plants well; avoid overhead watering; remove infected material promptly.
Slug damage to emerging shoots
Young shoots are vulnerable. Protect with iron phosphate pellets or copper tape collars around corm sites in spring.
Prevent waterfall gladiolus problems before they start
Most waterfall gladiolus issues are care-mismatch, not bad luck. Dial in the basics:
Waterfall Gladiolus problems — FAQ
Why is my waterfall gladiolus corm rot in cold, wet ground?
Not fully hardy in the UK or northern US climates. Lift corms after first frost, dry thoroughly, and store in cool, frost-free conditions over winter.
Why is my waterfall gladiolus thrips?
Tiny insects cause silver streaking on foliage and distorted flowers. Use insecticidal soap or neem oil spray; destroy heavily infested plants.
Why is my waterfall gladiolus fusarium wilt (dry rot)?
Corms rot from the base upward. Remove and destroy affected corms; avoid replanting in infected soil for several years.
Why is my waterfall gladiolus botrytis (grey mould)?
Affects stems and flowers in wet conditions. Space plants well; avoid overhead watering; remove infected material promptly.
Why is my waterfall gladiolus slug damage to emerging shoots?
Young shoots are vulnerable. Protect with iron phosphate pellets or copper tape collars around corm sites in spring.