Daikon

Daikon is a large, elongated type of radish, grown as an annual vegetable. Compared with small round radishes, it takes longer to mature, often 50 to 60 days to reach harvest. Radishes in general prefer the cool temperatures of spring and fall.

Sowing. Sow seed directly in the garden, about ¼ to ½ inch (0.6 to 1.3 cm) deep in rows 12 inches (30 cm) apart. Don’t start daikon indoors for transplanting, because radishes don’t transplant easily. A seed supplier suggests sowing about 10 seeds per foot and thinning, with rows 18 inches (45 cm) apart. Seedlings usually appear after 7 to 10 days.

Thinning and spacing. Thin daikon so the remaining plants stand 4 to 6 inches (10 to 15 cm) apart.

Timing. Daikon can be sown in early spring for a early-summer harvest, or in late summer for a fall harvest, and many gardeners prefer the flavor of the fall crop. Avoid growing it in summer heat, when radishes turn spongy, woody and overly hot and quickly form seed heads.

Site and soil. Choose a spot with full sun, at least six hours of direct light a day, and moist, well-drained, uncompacted soil. Long types do best when the soil is worked deeply, in raised beds if possible, which gives straighter roots and easier harvesting. Heavy, rocky or compacted soil tends to give small, misshapen roots, so raised beds or added compost help.

Watering. Keep moisture consistent, about an inch (2.5 cm) of water a week if rain doesn’t supply it. Drought stress makes radishes tough and poor in flavor.

Feeding. Don’t over-fertilize, since too much feed encourages lush tops and little root. Skip fresh manure, because the roots are eaten raw and fresh manure can carry disease-causing microorganisms.

Weeds and mulch. Weed with light cultivation so you don’t disturb the roots, and use an organic mulch to cut weeds, hold moisture and moderate soil temperature.

Overcrowding, or compacted or heavy soil, produces small, misshapen roots. Hot weather or harvesting too late gives hot, pithy roots, and too much nitrogen or sudden heat can give all tops and little root. Uneven watering can make roots split or taste overly hot. Occasional pests include flea beetles on the foliage and root maggots in the roots, and poorly drained soil can lead to root rot.

Daikon is ready roughly 7 to 10 weeks after planting. Dig the roots carefully with a spade or garden fork once they reach full size, typically 1 to 2 inches (2.5 to 5 cm) across and 8 or more inches (20+ cm) long. Harvest everything before frost, and don’t let roots get overly mature, as they turn fibrous and intensely flavored.

Cut the tops off, wash the roots and refrigerate them. A seed supplier gives 32 °F (0 °C) with 95% relative humidity as ideal, which can keep daikon roots for 6 to 10 weeks. In a home refrigerator, radishes in general keep about 2 to 3 weeks, so trim the foliage to within ½ inch (1.3 cm) of the root first.