How to grow
- Type: Cool season perennial, but usually grown as an annual.
- Light: Full sun.
- Soil: Well amended soil, good drainage.
- Water: Regular watering, likes moist soil.
- Size: Florence varieties typically 12-36" tall; Common and bronze can get as tall as 4-5'. Plant Florence varieties 8-12" apart.
When to plant/propagate
Fennel can handle light frost, and can be grown year-round in milder climates.
- From seed: Sow seeds February-April (maybe May), September-October (maybe August). If growing from seed for transplants, allow 4 weeks to be ready.
- Transplants: February-April (maybe May), September-October (maybe August).
- Cuttings: Not recommended.
- Harvest the bulb-like base when it is large and plump, 4–6" across, typically 60-90 days after transplanting. Cut just above the soil line.
- Pollen can be collected from flower blooms by shaking flower heads into a plastic bag.
- Pick leaves at any time during the growing season. Do not remove more than 1/3 of the foliage.
- Harvest seeds when flower heads turns brown. Cut the seedheads and place in a paper bag in a cool, ventilated, location. The seeds will fall off when dry and can then be collected.
- Not recommended
Common pests & diseases
- Fennel, UCCE Master Gardeners of Santa Clara County
- Fennel in the Garden, Utah State University Extension
- Florence Fennel, UC Master Gardeners of Sonoma County
Recommended Varieties for Santa Clara County*
- Di Parma OP: Superior bulbing fennel, large and uniform, with great flavor. Flowers attract beneficial insects, and swallowtail butterflies will lay eggs on the feathery greens. 24–36" tall. Plant 10–12" apart.
Also, see our list of Spring Garden Market Herbs.
*Many other varieties may also do well here in Santa Clara County. This list is based on UC Master Gardener trials, taste tests, and feedback from local growers.