How to Grow Fennel
General Information
| Botanical Name: | Foeniculum vulgare |
| Common Names: | Fennel, Sweet Fennel, Common Fennel, Florence Fennel |
| Plant Family: | Apiaceae |
| Type: | Perennial grown as an annual; Culinary/Medicinal/Aromatic; Cool to warm season |
| Our Favorite Varieties: | Florence, Zefa Fino, Bronze Fennel, Sweet Fennel |
Know Before You Grow
| Growing Zones: | 4–9 |
| Frost Hardy: | Light frost |
| Heat Tolerant: | Moderate |
| Stratification: | No |
| Rows, Beds, Containers: | Best in beds or rows; containers work if deep enough |
Starting from Seed
| When: | Start indoors 4–6 weeks before transplanting |
| Soil: | Seed Starting Mix |
| Depth: | ¼ inch |
| Water: | Keep evenly moist until germination |
| Germination: | 7–14 days |
| Up Pot: | Only if needed; fennel dislikes root disturbance |
| Light: | 14–16 hours bright light |
| Soil Temperature: | 60–75°F |
| Heat Mat: | Optional |
| Harden Off: | 7–10 days |
Row, Bed, Container Prep
| Soil: | Loose, well-draining, moderately fertile soil |
| pH: | 6.0–7.0 |
| Soil Depth or Pot Size: | 10–12 inches deep minimum; containers at least 12 inches deep |
| Trellis: | no |
| Fertilizer/Feed: | Mix a small amount of balanced fertilizer such as 5-5-5 into the soil before planting if soil is poor; avoid heavy feeding |
| Compost: | Mix 1–2 inches of finished compost into the top several inches of soil before planting |
Transplanting/Up Potting
| When: | After frost danger has passed and seedlings are still young |
| How: | Transplant carefully without disturbing roots |
| Depth: | Same depth as original container |
| Spacing: | 12–18 inches apart |
| Water: | Water deeply after planting |
| Mulch: | Add light mulch after plants are established |
Direct Sowing
| When: | Spring after frost danger passes, or late summer for a fall crop |
| Depth: | ¼ inch |
| Spacing: | Thin to 12–18 inches apart |
| Water: | Keep evenly moist until established |
| Light: | Full sun |
| # in Sq. Ft. Planting: | 1 plant per square foot |
Growing Care
| Fertilizer/Feed: | Feed lightly only if growth is weak; too much nitrogen causes soft growth and weaker flavor |
| Days to Maturity: | 60–90 days for bulbs; 90–120 days for seed |
| Water: | About 1 inch per week; keep moisture steady for bulb fennel |
| Pruning/Harvesting: | Harvest fronds as needed; harvest bulbs before they get tough; allow plants to flower and dry for seed |
| Mulching: | Add 1–2 inches of straw, shredded leaves, or fine mulch once plants are established; keep mulch 2–3 inches away from stems |
| Pollination: | Insect pollinated; flowers attract many beneficial insects |
Companions & Antagonists
| Plant Family: | Antagonists: |
| None | Beans |
| – | Tomatoes |
| – | Peppers |
| – | Dill |
| – | Coriander |
| – | Caraway |
| – | Most garden vegetables, and most herbs…and most other spices. |
Attracts & Repels
| Attracts: | Repels: |
| Bees | Fleas |
| Butterflies | Some flying insects |
| Hoverflies | – |
| Parasitic Wasps | – |
| Ladybugs | – |
| Swallowtail Caterpillars | – |
Pests & Disease
| Pests: | Disease: |
| Aphids | Powdery Mildew |
| Army Worms | Root Rot |
| Cutworms | Damping Off |
| Swallowtail Caterpillars | – |
Seed Saving
| When: | When seed heads turn brown and seeds are dry |
| Method: | Cut seed heads, dry fully in a paper bag or on a screen, then rub seeds free and store dry |
Harvest Time
| When: | Fronds anytime after established; bulbs when swollen and firm; seeds when fully dry |
| How: | Cut fronds as needed, cut bulb at soil line, cut dry seed heads |
| What: | Fronds, bulbs, seeds |
| Storing: | Fronds fresh short term; bulbs refrigerated; seeds stored dry |
| Preservation Methods: | Drying seeds, freezing fronds, dehydrating bulb slices |
Medicinal Uses:
| Traditionally Used for: | Gas, bloating, digestion, cough support, nursing support |
| Forms: | Tea, syrup, tincture, whole seed |
| Dosage or Application: | Tea: 1–2 teaspoons crushed seed per cup; Syrup: 1 teaspoon to 1 tablespoon as needed; Tincture: 20–40 drops |
| NOTICE: | This information is based on historical/traditional fact. It is for educational purposes only. Lowe Bridges Farm will not be held liable for your use of this information. Your use of this information and the results thereof is your responsibility, and yours alone. |
Culinary Uses:
| Flavor Profile: | Sweet, anise-like, mild licorice flavor |
| Best Used In: | Fish, sausage, soups, salads, roasted vegetables, breads, teas |
| Forms: | Fresh fronds, fresh bulb, whole seed, ground seed |
As an Aromatic:
| Used for: | Sweet licorice scent in teas, spice blends, and herbal preparations |
| How: | Dried seeds, fresh fronds, crushed seed |
Troubleshooting
| No Bulb Formation: | Planted too close, too hot, or inconsistent watering |
| Bolting: | Heat stress or drought stress |
| Tough Bulbs | Harvested too late or grown too dry |
| Poor Seed Set: | Not enough flowering time or poor pollinator activity |
| Weak Growth: | Soil too poor or plants too crowded |
