Flower · Paeoniaceae
When to sow peonies
The longest-lived plant in most gardens - a well-sited peony outlasts the gardener and resents being moved even once. Two weeks of flower a year, and foliage that stays respectable until autumn.
First worthwhile crop
Year 3
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, peonies 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 3 after planting.
- Hardy in USDA zones 3a–8a.
Getting the timing right
Plant bare-root crowns in autumn while dormant, and note the depth: the buds must sit no more than 3 to 5cm below the surface. Planting too deep is the single commonest reason a peony grows well and never flowers, and it will go on not flowering for years until it is lifted and reset.
Frost tolerance
Hardy to -35C and requires a cold winter - it needs a sustained period below about 4C to break dormancy, so it flowers poorly in zone 9 and not at all in the tropics. Late frosts sometimes brown the emerging red shoots without doing lasting harm.
Classified as very-hardy, with damage expected below -35°C (-31°F)-31°F (-35°C).