Fennel Seeds - Florence


Foeniculum vulgare

Licorice-flavored bulb used as a vegetable with leaves, stalks and seeds as a culinary herb. Moderately frost-tolerant. Full sun. Annual.
  • Planting Information
  • How to Grow
  • Seed Saving


Average Seed / ozSeed / 100' RowAverage Yield / 100' RowDays to Harvest
70001/2 oz40 lbs70-100
Planting SeasonIdeal Soil TempSunFrost Tolerance
Spring/Fall60-85°FFull SunModerately Tolerant
Sowing MethodSeed DepthDirect Seed SpacingSeeds Per Packet
Transplant or Direct Seed1/2"3-4"110
Mature SpacingDays to SproutProduction CycleSeed Viability
12"5-17Annual3-4 years

Florence Fennel is grown for its bulbous stem, which can be eaten raw, grilled or baked. It is also possible to eat the thicker stalks which sprout from the bulb, as they are similar to celery. 
You can start seeds directly in the garden in well amended soil at the time of your last frost. You can also start them inside about 4-5 weeks before your last frost date. Don’t start them too early in containers, their roots don’t like to be disturbed when they begin to mature. When planting your seeds, cover with no more than 1/8” of soil to not hinder germination. Fennel will size up best in full sun with consistent moisture, though be careful not to over-water or that could result in the bulbs splitting. It is rarely necessary to fertilize your fennel during the growing season. Once the bulb begins to form at the base of the stem, hill up the surrounding soil to cover it. This shades it from the sun and prevents it from turning green. This is known as "blanching", as it keeps the bulb white and sweet. Florence fennel bulbs can be harvested once they reach the size of a small tennis ball, usually in late summer/early autumn. Fennel bulbs will survive a frost or two, so there is no rush to harvest them as soon as the weather turns cold. However, you shouldn't allow the fennel bulb to grow too large, or it will turn bitter.

Fennel, Foeniculum vulgare
Pollination, insect; Life Cycle, perennial; Isolation Distance, ½ mile
All fennel are insect pollinated biennials that will cross readily with other varieties of fennel. Distance isolate by ½ mile, or pollinating by hand or screen caging also works very well. Fennel puts out flower umbels similar to dill, and are harvested in the same way. Cut the umbels into a paper bag and allow to further ripen indoors, shake the seed free and store when fully dry.