Growli

Overwintering guide

How to overwinter black calla lily

Verdict
Outside, protected
When
Mulch and move pots into shelter in late autumn, before the first hard frosts.
Hardiness
Black Calla Lily is hardy to roughly USDA zone 8 — winter lows around -12°C. That means it survives outside in mild areas, but wants shelter in a hard winter.

Winter watering

Water rarely, and only in dry spells — winter wet is a bigger risk than winter cold. Make sure containers drain freely.

The mistake that kills black calla lily in winter

Leaving black calla lily in a pot standing in a saucer of water. Waterlogged compost freezes solid around the roots and kills plants that would have survived the cold perfectly well.

More black calla lily care

Overwintering black calla lily — FAQ

Does black calla lily need to come indoors for winter?

Black Calla Lily is hardy to roughly USDA zone 8 — winter lows around -12°C. That means it survives outside in mild areas, but wants shelter in a hard winter. Black Calla Lily can stay outside over winter in most areas, but appreciates some protection in a cold snap. Mulch generously over the root zone, move containers against a sheltered wall (pots freeze far harder than open ground), and have horticultural fleece ready for the worst nights. The roots are what you are protecting — top growth can be sacrificed and regrown.

When should I move black calla lily for winter?

Mulch and move pots into shelter in late autumn, before the first hard frosts.

How often should I water black calla lily in winter?

Water rarely, and only in dry spells — winter wet is a bigger risk than winter cold. Make sure containers drain freely.

What kills black calla lily over winter?

Leaving black calla lily in a pot standing in a saucer of water. Waterlogged compost freezes solid around the roots and kills plants that would have survived the cold perfectly well.