Growli

Overwintering guide

How to overwinter royal flush split rock

Verdict
Keep frost-free
When
Move under cover before the first hard frost; back outside after the last spring frost.
Hardiness
Royal Flush Split Rock is hardy to roughly USDA zone 9 — winter lows around -7°C. That means it takes cool conditions but not a real freeze.

Winter watering

Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.

The mistake that kills royal flush split rock in winter

Bringing royal flush split rock into a warm living room. Too much winter warmth forces weak, pale growth that collapses when it goes back outside — cool and bright beats warm and dim.

More royal flush split rock care

Overwintering royal flush split rock — FAQ

Does royal flush split rock need to come indoors for winter?

Royal Flush Split Rock is hardy to roughly USDA zone 9 — winter lows around -7°C. That means it takes cool conditions but not a real freeze. Royal Flush Split Rock will take cool conditions but not a hard freeze, so the aim is a frost-free winter rather than a warm one. An unheated greenhouse, porch, conservatory or bright garage all work well. Keep it cool, bright and on the dry side, and it will hold steady until growth restarts in spring.

When should I move royal flush split rock for winter?

Move under cover before the first hard frost; back outside after the last spring frost.

How often should I water royal flush split rock in winter?

Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.

What kills royal flush split rock over winter?

Bringing royal flush split rock into a warm living room. Too much winter warmth forces weak, pale growth that collapses when it goes back outside — cool and bright beats warm and dim.