How to Grow Fennel in Containers
Foeniculum vulgare
Fennel offers delicate anise flavor in two forms: crunchy white bulbs for roasting and salads, or feathery fronds as an herb. Bronze fennel adds stunning bronze-colored foliage to container gardens while attracting swallowtail butterflies. Container growing keeps fennel contained and allows careful control of the conditions needed for bulb formation.
Best Fennel Varieties for Containers
Zefa Fino Florence Fennel (65 days)
Bolt-resistant bulbing variety. Large, tender white bulbs. Good for fall harvest. Best for: reliable bulb production.
Bronze Fennel (perennial)
Stunning bronze/purple feathery foliage. Ornamental and edible. Attracts butterflies. Doesn't form bulbs. Best for: ornamental herb gardens, visual interest.
Orion Florence Fennel (80 days)
Very large bulbs (up to 1 lb). Good bolt resistance. Sweet, mild anise flavor. Best for: maximum bulb size.
Frequently Asked Questions
What's the difference between bulbing fennel and herb fennel?
Bulbing fennel (Florence fennel) is grown for its anise-flavored white bulb, has a shorter season, and needs more careful culture. Herb fennel (bronze/green fennel) is grown for its feathery fronds as an herb and doesn't form a bulb - it's perennial, ornamental, and much easier to grow. Both flowers attract beneficial insects.
How big of a container does fennel need?
Bulbing fennel needs at least 12 inches deep and 10-12 inches wide to form proper bulbs. Herb fennel can manage with 8-10 inch pots. Both types have taproots that resent disturbance - use deep containers and avoid transplanting if possible.
Why won't my fennel form bulbs?
Bulbing fennel bolts without forming bulbs due to: transplant shock (direct sow instead), heat stress, long days (plant for fall harvest), inconsistent watering, or wrong variety (use 'Zefa Fino' or other bolt-resistant types). Herb fennel doesn't form bulbs - that's normal for that type.
Can fennel survive winter?
Herb fennel is perennial in zones 4-9 and will return each spring. Bulbing fennel is an annual - harvest before frost. Both types tolerate light frost. In cold climates, mulch herb fennel roots heavily or bring container to protected location.
When should I harvest fennel bulbs?
Harvest bulbing fennel when the white bulb is 3-4 inches across, firm, and tight. Cut at soil level. Don't wait too long - overmature bulbs become tough and pithy. Harvest before hot weather triggers bolting. The fronds are also edible - use like dill.
Why do butterflies love fennel?
Like dill, fennel is a host plant for swallowtail butterfly caterpillars. The flowers attract many beneficial insects including parasitic wasps and ladybugs. Bronze fennel is especially ornamental. Plant extra if you want to share with caterpillars!
Is fennel a bad companion plant?
Fennel has a reputation for inhibiting growth of many plants including tomatoes, beans, and peppers. In containers, this isn't usually an issue since plants are separated. But keep fennel in its own pot and don't plant directly with other vegetables.
Can I grow fennel from the grocery store?
Yes! Place the cut end of a fennel bulb in water until roots form (change water daily), then plant in soil. It won't regrow a full bulb but will produce fronds for herb use. A fun way to get free fennel plants.
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