Growli

Overwintering guide

How to overwinter black walnut 'sparks 147'

Verdict
Stays outside
When
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
Hardiness
Black Walnut 'Sparks 147' is hardy to roughly USDA zone 4 — winter lows around -34°C. That means it can stay outside all winter in most temperate gardens.

Winter watering

No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.

The mistake that kills black walnut 'sparks 147' in winter

Cutting black walnut 'sparks 147' hard back in autumn "to tidy up". That removes the growth that shelters the crown, and on some plants removes next season's flower buds entirely.

More black walnut 'sparks 147' care

Overwintering black walnut 'sparks 147' — FAQ

Does black walnut 'sparks 147' need to come indoors for winter?

Black Walnut 'Sparks 147' is hardy to roughly USDA zone 4 — winter lows around -34°C. That means it can stay outside all winter in most temperate gardens. Black Walnut 'Sparks 147' is properly hardy and overwinters outside without fuss. Tidy away anything dead or diseased, apply a mulch over the crown to steady soil temperatures, and otherwise leave it alone — many hardy plants actually need a cold period to flower and grow well the following year. Save hard pruning for the right season rather than doing it in autumn.

When should I move black walnut 'sparks 147' for winter?

Tidy and mulch in late autumn; leave the plant undisturbed until spring.

How often should I water black walnut 'sparks 147' in winter?

No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.

What kills black walnut 'sparks 147' over winter?

Cutting black walnut 'sparks 147' hard back in autumn "to tidy up". That removes the growth that shelters the crown, and on some plants removes next season's flower buds entirely.