Flower · Brassicaceae
When to sow honesty
Purple spring flowers followed by translucent papery seed discs that are the real reason to grow it - they last for years in a dry vase. Seeds itself around a garden politely rather than aggressively.
Plant out
20 weeks after
Counted from your last spring frost.
Sow direct
6 weeks after
Counted from your last spring frost.
Days to maturity
300-340
From sowing to a first picking.
Those weeks become real dates once you name a place.
Timing, in frost-relative terms
Seed packets rarely give calendar dates, because a date that suits one latitude is wrong at another. They give offsets from the last spring frost instead, and those offsets are what make honesty plantable anywhere.
- Plant out 20 weeks after the last frost.
- Sow direct 6 weeks after the last frost.
- Expect 300–340 days to maturity, counted from sowing.
- Hardy in USDA zones 4a–9a.
Getting the timing right
Sow in early summer, six weeks after the last frost, in shade or part shade. Move to the final position in autumn. Flowers the following April, then sets the discs through summer; cut the stems when the pods turn beige and rub the brown outer skins off to reveal the silver.
Frost tolerance
Hardy to about -20C as a rosette and needs winter cold to flower. Tolerates dry shade under trees better than almost any other flowering biennial.
Classified as very-hardy, with damage expected below -20°C (-4°F)-4°F (-20°C).