Grow In Cool Weather
Radishes are cool-season crops that can tolerate temperatures below freezing. Radishes like full sun and mature in as little as 20 – 30 days.
Radishes need to be grown in early spring or fall Start planting radishes from seed in the garden two to three weeks before the average date of last frost. Radishes germinate quickly
Sow radish seeds, 1/2 inch deep, as soon as the soil can be worked. Plant new seeds, about every eight days for a continuous crop until the hot summer weather arrives. Germination will take 4-12 days.
Thin seedlings to two inches apart in all directions. Radishes do not like to be crowded, and will not bulb properly if overcrowded by other radishes or weeds.
Radishes need consistent moisture. If the soil dries out during their growth, radishes will become bitter and mealy. Keep radishes evenly moist throughout the growing season. Use a mulch to help retain soil moisture.
Radishes are mature for a short time, if left in the ground too long radishes will become pithy and mealy.
Winter radishes take a longer time to grow and are divided in to 4 groups. Daikon radishes are like white carrots. Chinese or lo bok radishes are white and long. Spanish radishes are tart with black skins and white flesh. German Beer Radishes look like turnips.