Growli

Overwintering guide

How to overwinter split rock

Verdict
Keep frost-free
When
Move under cover before the first hard frost; back outside after the last spring frost.
Hardiness
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 split rock in winter

Bringing 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 split rock care

Overwintering split rock — FAQ

Does split rock need to come indoors for winter?

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. 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 split rock for winter?

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

How often should I water 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 split rock over winter?

Bringing 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.