When to plant radishes in USDA Zone 8b

Plan your radishes planting around local frost risk and soil temperature, then work backward from the harvest week your buyers need. The calendar below is a starting point, not a field-level weather forecast.

Charleston SC, Savannah, Mobile, Austin, Jacksonville. Average last spring frost March 15, first fall frost November 15 — a 245-day frost-free season.

Zone fit: excellent
Radishes is well suited to Zone 8b. Standard planting dates work with minor adjustments for microclimates.

Key dates

Direct-seed outdoors
February 8 – March 1
Expected first harvest
March 15 – April 12
Fall planting window
September 27 – October 18
Fall harvest window
November 1 – November 29

Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.

Spacing and soil

Plant spacing
1″
Row spacing
12″
Seed depth
0.5″
Soil temperature
45–70°F
Frost tolerance
hardy
Days to harvest
28 days

Grower notes for Zone 8b

Fastest crop in the garden. Interplant with slow germinators like carrots to mark rows.

Plant near: cucumbers, carrots, lettuce

Keep away from: hyssop

Other root crops for Zone 8b

Same crop, other zones

Track your own plantings

BAU Farm Intelligence turns these windows into per-field tasks — indoor seed-start reminders, transplant dates, harvest projections — using your farm's actual frost history.