Growli

Overwintering guide

How to overwinter dahlia 'bora bora'

Verdict
Outside, protected
When
Mulch and move pots into shelter in late autumn, before the first hard frosts.
Hardiness
Dahlia 'Bora Bora' 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 dahlia 'bora bora' in winter

Leaving dahlia 'bora bora' 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 dahlia 'bora bora' care

Overwintering dahlia 'bora bora' — FAQ

Does dahlia 'bora bora' need to come indoors for winter?

Dahlia 'Bora Bora' 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. Dahlia 'Bora Bora' 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 dahlia 'bora bora' for winter?

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

How often should I water dahlia 'bora bora' 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 dahlia 'bora bora' over winter?

Leaving dahlia 'bora bora' 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.