Endive and Radicchio

Endive and radicchio are closely related Mediterranean natives of the chicory (Chicorium) genus. Both have an appealing bitter flavor, some varieties milder than others. Leafy types are grown similarly to lettuce and are valued in raw or cooked cuisines. Their names are often applied interchangeably.

Endive

Endive, often pronounced “on-deev”, tolerates more heat while growing than lettuce but matures faster in cool weather which tempers the flavor. It is grown in 3 different forms:

a broad-leaf rosette, known as escarole, that resembles loose-leaf lettuce,
a curly-leaf form, 1 ft. or more wide, called frisée that also resembles some lettuces,
a root-crop form that produces cylindrical, blanched bulb-like growth forced above ground and known as French or Belgian endive or Witloof chicory.

Escarole and Frisée

Schedule very early spring sowing carefully to avoid growth during the hottest months, but success is best with late-summer plantings. Keep nitrogen levels low to avoid bolting.
Sow seed late in August-September for harvest in late fall and winter allowing 60-90 days to maturity. Or start seeds indoors 4-5 weeks earlier; thin plants to 10-12 inches apart.
Blanch heads before harvest to reduce bitterness by pulling outer leaves over the center and tying them one third of the way down. Heads must be completely dry to avoid rot.
Cover heads for 1-3 weeks to exclude all light for fully blanched yellow or white centers.

Belgian Endive

Look for special forcing varieties in seed catalogs. Plant in spring-early summer to mature by fall.
Prepare loose soil with ample compost added for excellent drainage and deep roots.
Trim green tops after 4 months of growth, leaving 1 in. of stem, and carefully dig the roots.
Dry roots in the open for a day or so, then bury diagonally in moist sand for storing in a cool, dark area to force pale, tender new growth above the thick, carrot-like roots.
Remove roots after a month or so and place in a 1 ft. deep flower pot with a drainage hole.
Set the pot in a tray of water in a cool, totally dark place for another 3 weeks until tender new bulb-like growth is evident and ready to eat.

Radicchio

Radicchio, often called red cabbage, is a red-leafed chicory, sometimes called Italian chicory or red endive. Round or elongated heads have firm, tightly packed leaves. Some varieties remain green.

Sow seed for red or green chicories (radicchio) in mid-late summer for maturity in cooler months. Some Dutch cultivars are bolt-resistant and fast-growing.
Sow seed ¼-½ in. deep and thin to 6-12 in. apart after seedlings are 1-2 in. tall.
Treat green varieties as a cut-and-come-again crop by breaking off a few tender outside leaves as needed; then, allow them to develop a partially full head.
Expect deep, rosy red varieties to deepen in color and lessen bitterness as weather grows cold.

Additional Information

Sonoma County Master Gardener Vegetable Planting Summary
https://sonomamg.ucanr.edu/Food_Gardening_with_Less_Water/

February 2022