Radishes

Growing Radishes in Zone 6b

A complete, zone-6b timeline for Radishes — when to start, transplant, and harvest, tuned to this zone's typical frost dates (St. Louis, Cincinnati, Boston).

April 16Last spring frost
October 22First fall frost
about 189 daysGrowing season
−10 to 0°FWinter low

Your planting timeline

  1. Direct sowonce soil warms, around April 16
  2. Harvestabout 22–35 days from transplant

Best varieties for zone 6b

Grow nearly anything — slip in colorful Watermelon and Green Meat winter radishes alongside fast salad types, timing main sowings for the cool ends of the season.

Growing notes

Even, consistent moisture is the single biggest factor in good radishes. Keep the soil steadily damp — never bone-dry, never waterlogged — so the roots swell quickly and stay mild and crisp. Irregular watering, especially a drought followed by a heavy soaking, causes the roots to split or turn pithy and unpleasantly hot. In dry spring weather that usually means a thorough watering every two to three days; in cool, damp conditions rainfall may be enough. Water at the base in the morning to keep foliage dry, and mulch lightly between rows to hold moisture and even out the soil temperature.

Recommended supplies

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