Common fennel, also called sweet fennel, is a cool-weather perennial herb grown as an annual. Sow common fennel seed in spring as early as 2 to 3 weeks before the average last frost date. Common fennel also can be sown in late summer or early fall for harvest before the first frost.
Description. Common fennel is grown primarily for its seed and leaves. It grows to 4 feet tall or more and has thin, thread-like leaflets atop tall, round, hollow stems. Common fennel flowers in late summer, small golden-yellow blossoms in umbrella-like clusters. Fennel’s small brown seeds follow flowering.
Yield. Grow one fennel plant per household.
Site. Plant fennel in full sun. Grow common fennel in well-drained soil rich in organic matter. Fennel prefers a soil pH of 6.0 to 6.7.
Planting time. Sow common fennel seed in spring as early as 2 to 3 weeks before the average last frost date. Common fennel also can be sown in late summer or early fall for harvest before the first frost. Fennel is half-hardy and will tolerate a light frost. Common fennel grows a taproot and is best sown in place.
Planting and spacing. Sow fennel seed ¼ to ½ inch deep; thin successful seedlings from 10 to 12 inches apart. Space rows 2 to 3 feet apart. Fennel re-seeds itself readily; plant it where it can grow for several seasons.
Water and feeding. Give fennel regular, even watering until it is established. Once established, fennel can be kept on the dry side. Side dress plants with aged compost at midseason.
Companion plants. Cucumbers, nasturtiums
Care. Common fennel can grow 4 to 5 feet tall and may require staking or supports, especially if it is growing in a windy spot. To make bulb fennel more tasty, mulch around the base of the plant to blanch the bulb and make it tender.
Container growing. Common fennel will grow easily in a container. Choose a container at least 12 inches deep; fennel forms a taproot.
Pests. Fennel is a member of the parsley family. Parsley caterpillars may attack fennel. Remove caterpillars by hand.
Diseases. Fennel has no serious disease problems.
Harvest. Common fennel will reach maturity in 60 to 70 days. Leaves can be snipped for fresh use once plants are 6 inches tall or more and established. Pick only the top 2 or 3 inches to ensure regrow. Leaves are best when harvested before flowering. Harvest the seeds of common fennel after flowering when they turn brown.
• Florence fennel (Foeniculum vulgare azoricum), also called, finocchio, is grown primarily for its stems and bulbous base.
• Bronze fennel (F. v. rubrum) is grown as an herb and ornamental plant.
Storing and preserving. Use common fennel leaves fresh. Fresh leaves also can be frozen in a plastic bag or dried and stored in an airtight container. Collect seeds when they dry but before they drop and re-seed. Place a paper under seed pods to collect the seed.
Common name. Fennel, common fennel, sweet fennel
Botanical name. Foeniculum vulgare
Easy grow herbs: THE KITCHEN GARDEN GROWERS’ GUIDE