Overwintering guide
How to overwinter penstemon 'sour grapes'
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills penstemon 'sour grapes' in winter
Cutting penstemon 'sour grapes' 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 penstemon 'sour grapes' care
Overwintering penstemon 'sour grapes' — FAQ
Does penstemon 'sour grapes' need to come indoors for winter?
Penstemon 'Sour Grapes' is hardy to roughly USDA zone 6 — winter lows around -23°C. That means it can stay outside all winter in most temperate gardens. Penstemon 'Sour Grapes' 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 penstemon 'sour grapes' for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water penstemon 'sour grapes' in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills penstemon 'sour grapes' over winter?
Cutting penstemon 'sour grapes' 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.