Chicory

Through winter, replant trimmed roots upright in damp sand in a bucket or box and hold them near 60 degrees in complete darkness. Radicchio types head up in roughly three weeks, Belgian endive closer to six. Force a few roots at a time rather than all of them. A root cut off from light drives its stored sugars into a blanched head instead of leaves, and any light leak turns that head green and punishingly bitter.

Fertilize a standing perennial chicory patch as it greens up in spring, and split the season's nitrogen rather than dumping it at once. Keep soil pH above 5.5, phosphorus near 25 ppm and potassium near 110 ppm, correcting from a soil test rather than by guess. Chicory is a heavy nitrogen feeder that regrows from the crown after each cutting, and the spring flush is where the plant rebuilds the taproot reserves it spent overwintering.

If you are not saving seed, cut the flowering stems down while the blue flowers are still open and before seed matures. Do not let a cultivated patch shed seed into surrounding ground. Chicory is naturalized across most of North America and self-seeds freely into fields and roadsides, and because its seed has no pappus to fly, it spreads exactly where soil, machinery and feet carry it out of your bed.

Sow chicory seed a quarter to a half inch deep in deep, well-drained fertile soil about a hundred days before your first hard frost. Count back from your own average first hard frost date rather than a calendar week borrowed from somewhere else: in the upper Midwest that lands in late June or early July, but in the warm end of the range it can be as late as September. Chicory grown for forcing or for roots wants that full run of long days. Forcing chicories are long-day crops that need 100-plus days to build the fat taproot the crop actually depends on, and a root that never sized up will not force a head no matter how you treat it later.

Once seedlings are up and handleable, thin or set plants every 10 to 15 inches, with rows about 12 to 14 inches apart. Pull the extras rather than crowding them along. Chicory heads and taproots both size up on the room they are given, and crowded plants trade head weight and root diameter for leaf that never makes a crop.

Check the young rosettes through the summer for slugs, snails and cutworms, looking under leaves and at the soil line where cutworms sever seedlings at night. Chicory has no serious pest problems, so hand-picking and cleaning up damp hiding places is usually the whole job. Chicory has no serious pest problems, and slugs, snails and cutworms are only occasional visitors - but they do their damage at the seedling stage, where losing a growing point costs you the entire plant rather than a few leaves. That asymmetry is why a low-probability pest is still worth a look.

Dig chicory roots in fall once a hard frost has knocked the tops back. Cut the green leaves off cleanly, leaving just the growing tip on the crown, and either roast the roots for a caffeine-free coffee or hold them for forcing at 32 to 35 degrees and 95 percent or higher humidity, where they will keep for months. The frost is the signal that the plant has finished pulling its sugars down into the taproot, which is both what makes the roasted root taste like coffee and what fuels the leafless head during forcing.