The Cool-Season Garden by Plant Family: Roots, Leaves and Heads

Carrot is the carrot family reference point: a biennial root vegetable and a domesticated form of the wild carrot, probably first cultivated in Iran for its leaves and seeds rather than its root. Orange from beta-carotene, though heirloom roots can be white, yellow, red, purple or black.

Parsnip is a close relative of both carrot and parsley in the same family, with a cream-colored taproot that turns sweeter after winter frost. It has been a vegetable since antiquity and served as a sweetener before sugar became common.

Beetroot is the taproot of a cultivated Beta vulgaris, native from the Azores and Western Europe to the Mediterranean and India. The same subspecies also gives sugar beet, Swiss chard and the fodder crop mangelwurzel, so one plant lineage covers sugar, greens and roots.

Spinach, from Central and Western Asia, sits in the amaranth family beside the beet. It is an annual that can overwinter in temperate regions, and blanching reduces its high oxalate content.

Radish opens the mustard family. Its large taproot is eaten raw as a crunchy, pungent salad vegetable, the sharpness coming from glucosinolate, myrosinase and isothiocyanate compounds, and the leaves are sometimes eaten too.

Turnip is the white, fleshy taproot of Brassica rapa grown in temperate climates. Small tender roots are eaten by people, larger ones fed to livestock, and in some regions the name is also applied to the related swede.

Cauliflower belongs to the same species as cabbage, broccoli, Brussels sprouts and kale. The part eaten is the dense head of undeveloped flower buds, the curd, and the Romanesco variety spirals in fractal patterns.

Kale is a group of cabbage cultivars grown mainly for edible leaves, bumpy, curly or flat, purple to green. It shows the same species as cauliflower pushed toward leaf instead of head.

Leek closes the walk in the onion genus Allium, which also holds garlic, shallot, scallion and chives. The edible part is a bundle of leaf sheaths, and elephant garlic and kurrat are cultivars of its wild parent species.