Raphanus sativus var. longipinnatus.
The "great radish" of Japan — dai-kon, literally "big root" — has been cultivated in East Asia for more than a thousand years, where it holds a place in daily eating comparable to that of the potato in Europe. Far from the little pink radish snacked at the aperitif, the daikon is a heavyweight: long pearly-white cylindrical roots reaching 30-40 cm long and 8 cm in diameter, weighing a kilogram or more, with dense, juicy, surprisingly mild flesh — far less pungent than Western radishes, almost sweet in the mouth.
Remarkable versatility, in Asian cooking and well beyond: finely grated and drained as daikon oroshi, that fresh light condiment served with tempura and grilled fish in Japan; yellow-pickled (takuan) in rice bran and turmeric; cubed for Korean kkakdugi kimchi; simmered for hours in Japanese oden or Korean beef broth until translucent and melting; julienned in Vietnamese bánh mì with carrot; or simply sliced as a flash pickle with vinegar and sugar. The leaves — often discarded — are actually delicious sautéed with sesame oil, like turnip greens. An unexpected garden bonus: the daikon's long taproot penetrates deep into compacted soils, creating channels of aeration and drainage — hence its use as a green manure on some farms in organic transition.
Grower's tip: The daikon is an autumn radish par excellence. Spring-sown, it tends to bolt before properly forming its root, under the influence of long days and heat. The right timing in Québec: late July to mid-August for a harvest from late September to November. Soil deeply loosened (minimum 30 cm of loosened earth, ideally 40), free of stones or fresh manure — the long root must be able to descend straight, and the slightest obstruction makes it fork. Harvest before hard frosts, but after a few cool nights that concentrate the sugars. Keeps several months in the root cellar in lightly damp sand.
- Open-pollinated. Annual to biennial depending on conditions. Insect-pollinated; crosses with other nearby radishes — isolate for seed saving.
- Height: 30-50 cm for the tops.
- Maturity: 50-70 days.
- Exposure: full sun.
- Soil deeply loosened (30-40 cm), free of stones or fresh manure, moderately rich. Thin to 10-15 cm.
- Direct-sow late July to mid-August for fall harvest. Spring sowing is possible but often disappointing — summer heat bolts the plant before the root forms fully. Tolerates light frosts well.
