Flower · Papaveraceae
When to sow bleeding hearts
Arching stems of pink hearts in spring, in shade. Dies back completely by midsummer, which is normal and not a failure, so it needs a neighbour to fill the gap.
First worthwhile crop
Year 2
After planting, not after sowing.
Hardy in USDA zones
3a to 8a
Winter cold sets the limit here, not the calendar.
Frost tolerance
Very hardy
How much cold the plant itself will take.
Those weeks become real dates once you name a place.
Timing, in frost-relative terms
Nothing about a standing crop is sown to a calendar. Once planted, bleeding hearts stay in the ground for years, so the question is not when to sow but whether your winter is survivable and your planting window is open. Both answers come from your frost dates.
- Expect a first worthwhile crop in year 2 after planting.
- Hardy in USDA zones 3a–8a.
Getting the timing right
Plant dormant crowns in autumn or very early spring, 5cm deep. Site it where the summer dieback will not leave a visible hole - behind a hosta or a fern is the usual answer. Do not water it in the hope of keeping the foliage; the dormancy is deliberate.
Frost tolerance
Hardy to -35C. Emerging shoots are brittle and damaged by hard late frosts, though the plant recovers. Requires a cold winter and does not grow well above zone 8.
Classified as very-hardy, with damage expected below -35°C (-31°F)-31°F (-35°C).