Radishes - Key Growing Information
SCIENTIFIC NAME: Raphanus sativus
CULTURE: Radishes require friable, well-drained soils with a pH range of 5.8–6.8. Sow at any time during the season, beginning in early spring. Use 2–3" wide bands, seeds about 3/4–1" apart (about 35 seeds/ft. except 10 seeds/ft. for 624 Red Meat and 616 Nero Tondo), 1/2" deep, rows 1' apart, or any row or bedding scheme that will eliminate unplanted ground to discourage weeds. For longer, straighter French Breakfast radishes, sow 15–20% more seeds per row than round radishes, 1/2 to 1 cm deeper, and do not irrigate unless absolutely necessary. Radishes are adversely affected by hot, dry weather. They remain in prime condition only a few days and should be grown rapidly with plenty of moisture to be mild, tender, and attractive. If growth is checked, roots may become tough, pithy, and too spicy.
INSECT PESTS: Use floating row covers at time of planting to control flea beetles and cabbage root maggots.
HARVEST AND STORAGE: Harvest promptly to avoid pithiness, beginning at about 3-4 weeks when roots are the size of a large marble. Bunch or top, hydrocool, and refrigerate. Topped radishes will keep 3–4 weeks in good, crisp condition if kept at 32°F (0°C), 95% relative humidity, and in breathable packaging. See product descriptions for longer storage of specialty types.
AVG. DIRECT SEEDING RATE: 1 oz./70', 14 oz./1,000', 21 lb./acre at 35 seeds/ft. in rows 18" apart, or 31 lb./acre in rows 12" apart.
SIZED SEEDS: Round red varieties only.
SEED SPECS: SEEDS/LB.: 36,500–61,200 (avg. 47,800).
PACKET: 250 seeds, sows 7'.