Fennel Seeds - Foeniculum vulgare

4, 5, 6, 7, 8, 9

USDA Zones 4-9 - Fennel grows as a hardy, short-lived perennial in these zones, often returning for several years. In all other zones, it is grown as a warm-season annual.

Best Performance in Zones 5-9 where it can easily overwinter. In these areas, it will develop a large taproot and grow into a more robust plant in its second and subsequent years, producing an abundance of foliage and seeds.

Northern Zones (4 and below) - Must be grown as an annual. Direct sow seeds after the last frost date. The long growing season required for seed production (90+ days) makes it suitable for these zones, but starting early is key.

Hot Climate Zones (South of Zone 9) - Can be grown, but may bolt prematurely in intense summer heat. In zones 10+, it is best planted in the fall for a winter and spring harvest, as it performs better in cooler, milder temperatures.

Soil Temperature - Germination is most successful when soil temperatures are between 60-75 degrees F.

Growing Season - Foliage can be harvested in as little as 60-70 days. For seed production, a longer season of 90-110 frost-free days is required for the plant to flower and the seeds to mature.

Learn more about USDA Hardiness Zones here

When to Plant:
Fennel develops a long taproot and does not transplant well, so direct sowing is strongly recommended. Plant seeds outdoors in the spring after all danger of frost has passed and the soil has warmed to at least 60 degrees F.

Where to Plant:
Choose a location that receives at least 6 hours of direct sunlight per day. Plant in well-drained soil. Fennel is not demanding, but rich soil will yield a more vigorous plant. Be mindful of placement; fennel can inhibit the growth of some plants, particularly bush beans, kohlrabi, and tomatoes. It is also known to cross-pollinate with dill, so separate them if you intend to save seeds.

How to Plant:

Prepare the garden bed by removing weeds and loosening the soil.

Sow seeds about 1/4 to 1/2 inch deep.

Plant seeds 4-6 inches apart in rows that are 2-3 feet apart.

Once seedlings are 2-3 inches tall, thin them to their final spacing of 10-12 inches apart to give them ample room to grow.

Water gently and keep the soil moist until germination, which usually takes 7-14 days.

Care & Maintenance:

Watering: Water seedlings regularly. Once established, fennel is fairly drought-tolerant, but consistent watering will produce more tender foliage. Avoid overwatering.

Fertilizing: Fennel typically does not require fertilizer and grows well in average soil.

Pests/Beneficials: Watch for the beautiful striped caterpillars of the Black Swallowtail butterfly. If you wish to support them, plant enough fennel to share!

Harvesting: You can begin snipping the feathery leaves (fronds) as needed throughout the growing season. To harvest seeds, wait until late summer or early fall after the flowers have faded and the seed heads have turned brown. Cut the stalks, place the seed heads in a paper bag, and hang in a cool, dry place. The seeds will fall off into the bag as they finish drying.