The most significant nutrient in radicchio is vitamin K followed by phytonutrients like anthocyanins. Often overlooked, vitamin K plays an important biochemical role in blood clotting and bone matrix building. It is needed for the activation of many proteins in the clotting process. The overall biochemical processes require more research, but thus far vitamin K appears to help encourage the formation of bone matrix (osteoblastic processes), while discouraging the breakdown of bone (osteoclastic processes). Responsible for the deep red color, anthocyanins are promising phytonutrients that have anti-inflammatory properties and inhibit the growth of pre-malignant cancer cells, induce apoptosis (programmed cell death) in cancer cells, inhibit angiogenesis (the growth of new blood vessels that feed tumors) and reduce cancer-causing DNA damage.
Vitamin and Mineral Content
Vitamins – K, B9 (Folate), C and E
Minerals – Copper, Manganese and Potassium
Early research suggests radicchio may help reduce the risk of osteoporosis, hemophilia and many types of cancers.
How to Grow
With its white-veined, deep red-purple leaves, radicchio is a great fall/winter veggie to add to a salad. Best time for planting is in late spring to early summer or late summer to early fall, depending on regional weather averages. The color and flavor of leaves develops in the transition to cooler temperatures. It may take a trial run to decide which one you like better. Radicchio prefers a sunny site with highly fertile moisture-retentive soil at a pH of 6.5. Amend the soil with a generous amount of aged compost or planting mix. Sowing seeds too early may cause the plants to run to seed. Start in late spring. Sow the seeds densely ¼ inch deep in shallow drills spaced about 1 foot apart. Later, thin the seedlings out to 9-10 inches apart. Keep the beds weed free and the soil moist, not soggy. If you let it dry out, they might become bitter. Right after first frost, remove outer leaves, leaving the curled interior leaves. Frost sweetens the leaf. Continue to keep the bed weed free and the soil moist. The colors should darken, and a head should begin to plump as weather cools. When the head gets plump and firm, they are ready for cutting.
Radicchio is insect resistant but may be bothered by slugs and snails. To trap them, embed a cup of beer into the soil so that the rim is flush with the soil. Snails and slugs are attracted to the beer, slide in, get stuck and drown. For other problems, ask your local nursery what might affect radicchio in your area.
When watering, soak the soil, not the foliage. This prevents any type of rotting.