A lovely heirloom radicchio, Rossa di Verona has deep red, heart shaped leaves wrapped tightly around one another to form a solid, round head. Later and hardier than Treviso, it has a sharp flavour that mellows when grilled or treated with a hot oil dressing. Sow Rossa di Verona chicory seeds in May/June and transplant in July for fall harvest. Cut off all the leaves above the crown in early fall. It's the resulting new growth in cold weather that produces the characteristic small, compact, cabbage-like head. They can even be overwintered for spring harvest.
Mark Recommends: Even if you have to go to a farmers market and buy a radicchio, you must try them grilled. Pull off the outermost wrapper leaves, and then cut the head into quarters down the core. Drizzle each of these with olive oil and sprinkle with sea salt and fresh black pepper. Pop them on the barbecue, right over a medium flame. In only a couple of minutes they will soften and begin to scorch. Allow this to happen on all sides, and then serve them hot with some balsamic vinegar. The cooking brings out an incredibly sweet flavour and knocks back all that bitterness of the raw product. Summertime doesn't work without grilled radicchio!
Matures in 85 days. (Open-pollinated seeds)
The chicory family includes the food plants endive and radicchio, which range widely in shape, and in flavour from bitter to sweet. All varieties become sweeter, and lose much of their bitterness, when cooked. Try a hot oil salad dressing over endive, or a barbecued head of radicchio. Continue reading below for tips on how to grow endive and radicchio from seed.
Cichorium endiva (endive) & C. intybus (radicchio)
Endive is easy.
Radicchio is moderately difficult.
Belgian endive (witloof) is downright challenging – but worth the effort.
Season & Zone
Season: Cool season
Sow after the last frost date and again in mid-summer to take advantage of the fall growing season. Optimal soil temperature: 10-22°C (50-72°F). Seeds sprout in 2-15 days, depending on conditions. In hot weather plants may go to seed quickly, so have new plantings ready to go.
Either direct seed or start indoors and transplant. Sow seeds 5mm (¼”) deep, and thin or transplant to allow 30-45cm (12-18″) between plants in rows 30-45cm (12-18″) apart.
Days to Maturity
From direct sowing.
Ideal pH: 6.0-6.5. Enrich soil with compost and add ¼ cup balanced organic fertilizer into the soil beneath each transplant. Rapid, continuous growth is essential for good yields and high quality. Regular watering is essential. Fall plantings can be protected from rain by putting a cloche over them. Endive heads can be blanched to reduce bitterness by placing a cardboard or plastic disc on top. Radicchio requires a good supply of phosphorus and potassium, but will not head and may bolt if there is too much nitrogen available. Days to maturity shown are from date of direct sowing. If transplanting, subtract 10-15 days.
Use as a cut and come again crop or let the heads develop and cut at ground level. Many will grow back.
In optimal conditions at least 65% of seeds will germinate. Usual seed life: 3 years. Per 100′ row: 140 seeds, per acre: 40.6M seeds.
Diseases & Pests
Aphids – Water can be used to remove aphids from plants. Wash the plant off with water occasionally as needed early in the day.
Moulds and rot from heavy rains can be prevented by growing under cover. Tip burn is a calcium deficiency within the plant that can be caused by an imbalance with over nutrients. Make sure to add lime to the soil, do not over-fertilize, and harvest just before full maturity.