Growli

Overwintering guide

How to overwinter heart-leaved blechnum

Verdict
Outside, protected
When
Mulch and move pots into shelter in late autumn, before the first hard frosts.
Hardiness
Heart-leaved Blechnum 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 heart-leaved blechnum in winter

Leaving heart-leaved blechnum 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 heart-leaved blechnum care

Overwintering heart-leaved blechnum — FAQ

Does heart-leaved blechnum need to come indoors for winter?

Heart-leaved Blechnum 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. Heart-leaved Blechnum 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 heart-leaved blechnum for winter?

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

How often should I water heart-leaved blechnum 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 heart-leaved blechnum over winter?

Leaving heart-leaved blechnum 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.