How to Grow Florence Fennel

Fennel FlorenceFlorence fennel is a cool-weather perennial grown as an annual. Fennel can be sown in the garden as early as 2 to 3 weeks before the average last frost date in spring. Florence fennel, which is grown for its bulbous stalk, requires 90 to 115 frost-free days to reach harvest. For an autumn crops sow fennel in mid- to late-summer.

Description. Florence fennel or finocchio is grown primarily for its bulbous base and leaf stalks which are used as vegetables. Fennel is a stocky plant which can grow to 24 inches tall and looks something like celery with fleshy stalks and feathery leaves. A taller cultivar of fennel known as common or sweet fennel is grown for its leaves and seeds which are used as herbal seasonings. Fennel produces a flat-topped cluster of small, golden flowers. Both Florence fennel and common fennel are members of the parsley family.

Yield. Plant 5 Florence fennel plants for each household member.

Site. Grow fennel in full sun. Plant fennel in well-drained soil rich in organic matter. Prepare the bed in advance by working in aged compost. Fennel prefers a soil pH of 5.5 to 6.8.

Planting time. Florence fennel is a cool-weather perennial grown as an annual. Fennel can be sown in the garden as early as 2 to 3 weeks before the average last frost date in spring. Seeds germinate best at 60°F. Fennel will tolerate heat and cold but does best when it comes to maturity in cool weather. Fennel requires 90 to 115 frost-free days to reach harvest. For an autumn crop sow fennel in mid- to late-summer.

Planting and spacing. Sow fennel seed a ¼ inch deep 4 to 6 inches apart. Thin successful seedlings to 12 inches apart. Space rows 24 to 36 inches apart.

Water and feeding. Keep fennel on the dry side; the soil should be evenly moist but not wet. Mulch to retain soil moisture in hot regions. Prepare planting beds with aged compost. Side dress fennel with aged compost at mid season.

Companion plants. Mints and members of the mint family.

Care. Blanch the lower stems when the bulbous base grows to the size of an egg; do this by mulching up around the bulb–the bulb will be more tender and sweet at harvest. Remove seed stalks to increase the production of stems and bulbs. Fennel will self-seed if left unattended.

Container growing. A single fennel will grow in a 6-inch pot; in larger containers grow Florence fennel on 8-inch centers. Spring plantings will not produce a large bulb. Plant in fall so that the plant comes to maturity in cool weather.

Pests. Fennel may be attacked by the parsley caterpillar. Remove it by hand. Generally, fennel has no other serious pest problems.

Diseases. Fennel has no serious disease problems.

Harvest. Fennel’s bulbous stalk can be harvested when it is 3 inches or more in diameter. Cut the whole stalk like celery just below the point where individual stalks join together. Cut leaves as needed once they have reached 18 inches tall. Florence fennel will be ready for harvest 90 to 115 days after sowing. Common fennel sprigs can be cut for flavoring once the plant is established.

Varieties. Hearld for spring planting. Zefa Fino, Rudy, and Trieste have large, flavorful bulbs.

Storing and preserving. Fennel is best eaten fresh. Florence fennel will keep in the refrigerator up to 1 week or in a cold moist place for 2 to 3 months. Stalks can be frozen or dried. Fennel leaves can be frozen or dried as herbs; dried leaves should be kept in an airtight container.

Common name. Fennel, Florence fennel, finocchio, fenucchi

Botanical name. Foeniculum vulgare dulce

Origin. Mediterranean

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