Overwintering guide
How to overwinter silky petrocosmea
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 silky petrocosmea in winter
Leaving silky petrocosmea 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 silky petrocosmea care
Overwintering silky petrocosmea — FAQ
Does silky petrocosmea need to come indoors for winter?
Silky Petrocosmea 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. Silky Petrocosmea 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 silky petrocosmea for winter?
Mulch and move pots into shelter in late autumn, before the first hard frosts.
How often should I water silky petrocosmea 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 silky petrocosmea over winter?
Leaving silky petrocosmea 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.