Seed-start answer
Radishes is usually direct-sown around Mar 13
In ZIP 19103, radishes is usually direct-sown around Mar 13 instead of started indoors.
Source: philadelphia-intl frost station, USDA zone 7b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.
This uses ZIP 19103, the Philadelphia frost station, and the Apr 10 last-frost estimate.
Seed starting schedule
Radishes dates for Philadelphia, PA
| Step | Date | How to use it |
|---|---|---|
| Direct Sow | March 13, 2026 | Sow seed outside when the crop and soil can handle the window. |