Troubleshooting
Six Hills Giant Catmint problems — and how to fix them
Six Hills Giant Catmint (Nepeta x faassenii 'Six Hills Giant') 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.
Heavy flopping
Its height makes splaying almost guaranteed by midsummer. Provide twiggy supports early, or shear the whole plant by half after the first flush to rebuild a denser, self-supporting mound.
Powdery mildew
White coating in humid, crowded plantings. Space generously, cut out affected stems, and water at the base rather than overhead.
Crown rot in wet sites
Collapse and blackening at the base in poorly drained or winter-wet ground. Plant high in sharply drained soil to keep the crown dry.
Cat damage
The scent draws cats that roll on and crush the clump. Cage or stake young plants until the crown is large and established.
Prevent six hills giant catmint problems before they start
Most six hills giant catmint issues are care-mismatch, not bad luck. Dial in the basics:
Looking for six hills giant catmint in general rather than its problems? Read the full six hills giant catmint care guide — light, water, soil and feeding.
Six Hills Giant Catmint problems — FAQ
Why is my six hills giant catmint heavy flopping?
Its height makes splaying almost guaranteed by midsummer. Provide twiggy supports early, or shear the whole plant by half after the first flush to rebuild a denser, self-supporting mound.
Why is my six hills giant catmint powdery mildew?
White coating in humid, crowded plantings. Space generously, cut out affected stems, and water at the base rather than overhead.
Why is my six hills giant catmint crown rot in wet sites?
Collapse and blackening at the base in poorly drained or winter-wet ground. Plant high in sharply drained soil to keep the crown dry.
Why is my six hills giant catmint cat damage?
The scent draws cats that roll on and crush the clump. Cage or stake young plants until the crown is large and established.