How to Grow Sweet Rocket
Hesperis matronalis
Hardy Cool Season
Sweet Rocket is a hardy biennial sown in summer, overwintering as a leafy rosette and bursting into fragrant purple, pink, or white flower spikes in late spring. Plant in any reasonable soil in sun or partial shade. Almost no care needed — just deadhead to control spreading or leave seedheads to self-sow freely and naturalise.
When to Start
Direct sow outdoors as soon as soil reaches 10°C — typically early to mid spring. Hardy enough to tolerate light frosts.
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Growth Stages
Sow seeds
Day 0 Germination
~14 days Flowering
~300 days Seed to harvest ~300 days
Approximate days from start
Care Essentials
- Generally no feeding needed. On poor soils, a balanced fertiliser at planting time is sufficient.
- Sweet Rocket is a short-lived biennial or perennial that self-seeds prolifically. Sow in summer, overwinter as a rosette, and enjoy fragrant flowers the following spring. Extremely low maintenance once established.
Growing Conditions
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- Direct sow
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Spacing & Planting
| Plant spacing | 45 cm |
| Row spacing | 45 cm |
| Mature height | 80 cm |
| Mature spread | 40 cm |
Frequently Asked Questions
- How far apart should I plant Sweet Rocket?
- Plant Sweet Rocket 45cm apart with 45cm between rows.
- Is Sweet Rocket frost hardy?
- Sweet Rocket is classified as Hardy.
