PlantSowGrow
How to grow Honesty
Lunaria annua
Purple spring flowers loved by orange-tip butterflies, followed by silvery, moon-like seed pods for winter arrangements. Happy in shade.
At a glance: Sow mid May to late June.
When to sow, plant and harvest
Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.
Growing Honesty: what it needs
- Light
- Part shade · 4+ hours a day
- Watering
- Keep moist while young; water in dry spells
- Soil
- Moist, well-drained soil
- Spacing
- 30 cm
- Height
- 75 cm
- In pots
- Grows well in containers
- Feeding
- A little general feed in spring
- Hardiness
- USDA zones 4–9
Step by step
- Mid May – late June · 4 weeks after the last spring frost
Sow Seeds
Sow thinly in trays or pots of seed compost, outdoors in a shady spot or in a cold frame.
- 10–21 days after “Sow Seeds” · Late May – early June
Check Germination
Seedlings appear in 10–21 days. Keep the compost moist.
- 14–28 days after “Check Germination” · Early June – late June
Pot On Seedlings
Move seedlings into their own 9 cm pots and grow them on through the summer.
- Early September – early October · 6 weeks before the first autumn frost
Plant Out for Next Year
Plant into their flowering positions 30 cm apart. They make leaves this year and flower next April–May.
- 200–240 days after “Plant Out for Next Year” · Late March – early May
Flowering — Enjoy and Deadhead
Your plants should flower around April–May. Remove faded spikes to encourage more, or leave some to self-seed.
- 45–75 days after “Flowering — Enjoy and Deadhead” · Early May – early June
Clear or Let Self-Seed
After flowering, pull out spent plants — or leave a few to drop seed for next year.
