When to Plant Radish in Iowa

Growing Radish in Iowa: Complete Guide

Radish (Rhaphanus sativus) is a crop that grows best when sown directly in the garden. In Iowa, the right time to direct sow is around Saturday, March 14, 2026, once soil temperatures are consistently warm enough for germination.

Because Iowa stretches across 4 USDA hardiness zones (4b, 5a, 5b, 6a), planting windows can shift by as much as two to four weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.

With 25 days to maturity, Radish fits comfortably within Iowa's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.

Radish requires full sun to partial shade and regular (keep moist) moisture. Midwest growing seasons are compressed between late spring frosts and fall cold snaps, so timing transplants precisely pays off.

For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Iowa.