How to grow radicchios

Radicchio is a heading chicory grown for wine red, white ribbed leaves that bring a bitter, crisp edge ordinary lettuce cannot match. Gardeners time it as a cool season crop, aiming for the head to fill out in autumn and early winter, since the deep color it is known for develops as temperatures drop rather than in summer heat. Early growth on a young plant is green and noticeably more bitter than the finished head; color shifts toward maroon as cooler nights set in. It occupies a bed much like lettuce, without the long commitment of a root crop left overwinter.

The hardest part of growing radicchio well is timing around heat. The University of California notes summer warmth pushes the plant to bolt and scorch its leaf tips, which is why late summer sowing is recommended in warm regions over a spring start. A second year gardener who sows in spring, expecting a lettuce-like turnaround, often gets plants that bolt before heading, or heads that stay green and bitter instead of tight and sweetened by cold. The fix is not more water or fertilizer; it is planting later so heading lines up with cool weather.