Botanical Name: Foeniculum vulgare var. azoricum
Native: Africa, Asia, and Europe
Hardiness: Perennial in USDA zones 4–9; grown as an annual.
Plant Dimensions: Foliage from 2'–4' tall; the "bulb", 3"–4" diameter at the base
Variety Information: The crunchy, dense, licorice-flavored "bulb" is comprised of tightly layered, overlapping, swollen stalk ends. The feathery foliage looks similar to dill, but has a delicate, anise flavor. The seeds also taste similar to anise or licorice. 'Romanesco' is a florence type fennel.
Exposure: Full sun
When to Sow Outside: "For "bulb": Midsummer for fall harvest is optimal; ideal soil temperature is 60°–75°F. In cool summer areas (under 75°F): 1 to 2 weeks after average last frost. Mild Climates: Sow in fall for cool season harvest. For foliage only: Every 3 weeks after average last frost until midsummer.
When to Start Inside: 4 to 6 weeks before average last frost (recommended for spring "bulb" production). Use biodegradable pots for transplant.
Days to Emerge: 7–14 days
Seed Depth: ¼"
Seed Spacing: A group of 3 seeds every 10"
Row Spacing: 10"
Thinning: When 1" tall, thin to 1 every 10"
Harvesting: BULBOUS STEM BASE: Harvest any time after the base begins to fatten, and before plant begins to bolt. Cut just below the soil surface. LEAVES: Can be clipped for fresh use almost any time after plant becomes established. SEEDS: Harvest seeds when they turn from yellow green to grey green. If allowed to turn brown, they may fall to the ground before you can harvest them.