(Cichorium intybus) Radicchio is a member of the chicory family, prized for its flavorful leaves and stunning colors. It was cultivated as early as the 15th century. It is used like lettuce to make beautiful, tasty salads, and is good cooked as well. Directly sow for a fall harvest. Radicchio grows best when planting is timed to mature in cool weather. Sow in late summer to mature when the weather gets cold; the cold will bring the best flavors to light! Surface sow seeds and rake in lightly, barely covering the seeds. Seeds will usually germinate quickly if kept very moist. Ideal germination temperature is 70F, but seeds can germinate in soil temps down to the 40s. Space plants 12 inches apart. Plants prefer rich, loose, well-drained soil that is high in nitrogen and at least one inch of rain weekly. Water deeply during dry spells. Consider mulching your crop to suppress weeds and retain moisture.