PlantFiles: Radicchio, Italian Chicory
Cichorium intybus 'Adria'

A large red heading cultivar.
"Radicchio performs best under cool temperatures and is therefore grown in early spring or late fall. Varieties are available for summer (July and August) harvest. Red leaf Radicchio develops its best color, and grows best under cool fall or spring temperatures, however some varieties (see above) can be grown in Western Oregon and Washington throughout the summer.

Plant as early in the spring as possible and stagger plantings once or twice per week, planting only what can be harvested and sold during that interval. " Oregon State University