The wild form of this Mediterranean native, known botanically as Cichorium intybus, grows as a perennial roadside weed 24 feet tall in much of the South and is recognized by its pretty sky-blue flowers. Different chicories are grown for three purposes: for salad greens (small-rooted types); for roots to make a coffee substitute (large-rooted types); and for Belgian or French endive ('Witloof' chicory). To grow 'Witloof', sow seeds in spring or early summer; plants will mature by fall. In winter, trim the greens to an inch of stem; then dig the roots, bury them diagonally in moist sand, and set in a dark, cool room until pale, tender new growth has been forced. (For the standard salad green called endive, see Endive.)
Radicchio is the name given to red-leafed chicories grown for salads. 'Indigo', 'Rossa de Verona' ('Rouge de Verone'), 'Red Treviso', and 'Rossana' are good selections. Radicchio makes lettucelike heads that color to a deep rosy red as weather grows cold in fall or winter; its slight bitterness lessens as color deepens. Best sown in mid- to late summer to mature in cool fall months, though the selection 'Giulio' can be sown in spring to harvest in summer. Sow green-leafed chicory beginning in early spring (and up to early summer where that season is not too hot); in areas with mild winters, you can also plant in mid- to late summer for fall and winter harvest.
Sow both green and red types 1412 inches deep; thin seedlings to 612 inches apart. Before planting, work into the soil 12 cup of 10-10-10 fertilizer per 10 feet of row.