How to Grow Honesty
Lunaria annua
When to Start
Direct sow outdoors as soon as soil reaches 5°C — typically early to mid spring. Can also be started indoors 4 weeks earlier for a head start.
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Growth Stages
Approximate days from start
Care Essentials
- Rarely needed. Thrives in average to poor soil — rich soil produces lush leafy growth at the expense of flowers and pods.
- Hardy biennial beloved for its papery silver seed pods used in dried flower arrangements. Tolerates partial shade and self-seeds freely. A brassica relative — rotate away from other brassicas to avoid clubroot.
Companion Planting
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Growing Conditions
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- Sow indoors
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- Transplant out
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- First harvest
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Spacing & Planting
| Plant spacing | 30 cm |
| Row spacing | 40 cm |
| Sow depth | 1 cm |
| Mature height | 75 cm |
| Mature spread | 30 cm |
Hardy biennial grown for its translucent silvery seed pods. Tolerates partial shade — good for woodland edges and shady borders. Self-seeds freely once established.
Care Guide
- Feeding
- Rarely needed. Thrives in average to poor soil — rich soil produces lush leafy growth at the expense of flowers and pods.
- Watch for
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- Caterpillars (cabbage white)
- Aphids
- Slugs
- Clubroot
- White blister
Pests & Diseases
Pest Caterpillars (Cabbage White)
Identification: Irregular holes in leaves, green or yellow caterpillars visible on foliage, frass (droppings) present on leaves
- Pick caterpillars off by hand
- Use fine mesh netting to exclude butterflies
- Apply Bacillus thuringiensis (Bt) biological spray
- Spray with a contact insecticide containing deltamethrin or lambda-cyhalothrin
Pest Aphids
Identification: Clusters of grey-green or black insects on shoot tips and undersides of leaves, causing distorted growth and sticky honeydew
- Blast off with a strong jet of water
- Spray with fatty acid-based insecticide
- Encourage ladybirds, lacewings and hoverflies
- Spray with a contact insecticide containing deltamethrin or lambda-cyhalothrin
Pest Slugs and Snails
Identification: Irregular holes in young leaves and slime trails around plants, worst in wet weather
- Use beer traps or copper tape barriers
- Apply organic slug pellets (ferric phosphate)
- Encourage natural predators such as hedgehogs and ground beetles
- Ferric phosphate-based pellets
Disease Clubroot
Symptoms: Plants wilt during the day and recover at night; roots become swollen and distorted; plants stunted and yellow
Treatment: No cure once infected — remove and destroy affected plants. Do not compost. Lime the soil to raise pH above 7.0 to discourage future outbreaks
Prevention: Rotate brassica-family plants on a minimum four-year cycle; avoid planting in waterlogged soil; raise transplants in modules to give them a strong start
Disease White Blister
Symptoms: Chalky white pustules on the undersides of leaves, with corresponding pale or distorted patches on upper surfaces; affected stems may become swollen and distorted
Treatment: Remove and destroy affected leaves and stems. Improve air circulation around plants
Prevention: Space plants well, avoid overhead watering, and rotate away from other brassica-family plants each year
Growing Conditions
| Min. soil temperature | 5°C |
| Germination temperature | 15–20°C |
| Base growth temperature | 4°C |
| Min. daylength to start | 9h |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Honesty?
- Plant Honesty 30cm apart with 40cm between rows.
- When does Honesty flower?
- Honesty typically flowers approximately 60 days after transplanting.
- Is Honesty frost hardy?
- Honesty is classified as Hardy.
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