key growing information

Growing Radish: How to Plant, Grow & Harvest

How to grow radishes: soil and pH, fast growth for mild roots, succession sowing and spacing, French Breakfast tips, rates, flea beetle protection, harvest and storage.

By Hensley’s Seed Co. September 3, 2026

Radishes - Key Growing Information

Bunch of freshly harvested radishes of a uniformly round, pastel pink type, with medium-sized tops.

SCIENTIFIC NAME:

Raphanus sativus

CULTURE:

Radishes need loose, crumbly, well-drained soil with a pH of 5.8–6.8. Hot, dry weather hurts them. They stay at their best for only a few days, so grow them quickly with plenty of water for mild, tender, good-looking roots; any check in growth can make them tough, pithy and overly hot.

DAYS TO MATURITY:

Counted from direct sowing. DIRECT SEEDING: Sow any time in the season from early spring on, ½" deep in bands 2–3" wide with seeds about ¾–1" apart (roughly 35 per foot) and rows 1' apart. For longer, straighter French Breakfast radishes, sow 15–20% more seed per row than for round types, ½–1 cm deeper, and water only when truly needed.

AVG. DIRECT SEEDING RATE:

About 70' per oz., 14 oz. per 1,000', or 31 lb. per acre in 12" rows.

INSECT PESTS:

Use floating row covers put on at planting keep flea beetles and cabbage root maggots away.

HARVEST:

Start pulling at about 3–4 weeks, when roots are the size of a big marble, and harvest promptly before they turn pithy. STORAGE: Bunch or top, hydrocool and refrigerate. Topped radishes stay crisp for 3–4 weeks at 32°F (0°C) and 95% relative humidity in breathable packaging. Some specialty types store longer; see their descriptions.

SIZED SEEDS:

"Sized" seed has been sorted to a uniform size, which makes spacing with mechanical seeders more accurate and germination more even. Only the round red radishes are sized.

SEEDS/LB.:

From 36,500 to 61,200, averaging 47,800.

PACKET:

250 seeds per packet, enough for about 7'.