Fennel is a semi-hardy perennial making it through the winter here about 50% of the time. This variety is grown for its leaves and anise-flavored seeds and can grow up to 4-6 feet. These decorative fern-leaved plants can be started indoors or out and grown as an annual in colder parts of the country. Plant toward the edges or borders of vegetable gardens. Fennel is said to not be a good companion when planted too closely with other vegetables, especially beans, tomatoes, dill, and carrots.
Tender Perennial, zones 6,7-10
Germination: 7-14 days
Germination Temperature: Optimum soil temperatures 65-70ºF
Seed Planting Depth: Sow ¼” deep
Starting Indoors: Start indoors 4-6 weeks before the last frost. Provide 65-70ºF soil temperatures. Using peat, cow, or paper pots can help with the stress of transplanting, they grow delicate roots and successful transplanting may be challenging. Transplant after the last frost, 6-8” apart.
Sowing Outdoors: Mid-spring when the soil temperature reaches 60-65ºF. Sow seeds close, 1-2" apart, thin to 6-8” apart.
Growth Habit: Upright, branching
Height and Width: 36-48” x 18-24”
Spacing: 6-8” apart
Light Needs: Full sun
Soil Needs: Fennel needs average to fertile, well-drained soil
Flowering: Mid to late summer, 65-70 days
Harvest: Start when the plants are 8-12”, picking leaves as needed. Collect seeds when umbels turn from green to brown and before they shatter to the ground. Place in a paper bag until they are fully ripened and dry.
Uses: Culinary, medicinal, flower gardens beds and borders, filler for flower arrangements, flowers attract butterflies, bees and beneficial insects
Care: Water well during prolonged dry periods in summer. Removing flower stalks helps keep the plant producing leaves for a longer period. Fennel reseeds easily in mild climates,-removing flower heads helps decrease next season volunteers. Providing support can help when the plants get tall. Can be grown in containers.