Overwintering guide
How to overwinter tree rhododendron
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills tree rhododendron in winter
Cutting tree rhododendron 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 tree rhododendron care
Overwintering tree rhododendron — FAQ
Does tree rhododendron need to come indoors for winter?
Tree rhododendron is hardy to roughly USDA zone 7 — winter lows around -18°C. That means it can stay outside all winter in most temperate gardens. Tree rhododendron 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 tree rhododendron for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water tree rhododendron in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills tree rhododendron over winter?
Cutting tree rhododendron 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.