Plant Radishes in Zone 12b
Seed-starting, transplant & harvest dates for USDA Zone 12b
Zone 12b is effectively frost-free, so the Zone 12b calendar for radishes is set by heat, not cold. There is no last frost to count backward from and no first frost to beat, which means the question is not whether radishes will finish but whether it will sit through the hottest stretch of the year. Radishes is a hardy crop needing about 28 days from sowing to harvest.
Planting radishes for a fall harvest in Zone 12b
Zone 12b has no meaningful frost, so the fall and winter months are the easiest time of year to grow radishes here. Sow from about October 1 onward.
Radishes are the fastest fall insurance crop. Fall roots stay milder and split less than spring ones because the soil is cooling rather than heating.
Fall dates are counted backward from the Zone 12b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall radishes in Zone 12b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Feb 1 | Feb 1 | Mar 1 |
| Fall | Oct onward | Oct onward | Winter |
Radishes in nearby zones
Further reading on radishes
- Cold frame gardening by zone
How a cold frame keeps radishes producing into winter, and when to sow it.
- Last frost date and what to plant before it
Why radishes can go out before your last frost, and how far before.
- Best raised garden beds for beginners
Loose, deep soil is most of what root crops need.
Other crops in Zone 12b
Frequently asked questions
When should I start radishes in Zone 12b?
Direct sow outdoors around Feb 1.
Can I direct sow radishes in Zone 12b?
Yes, direct sow around Feb 1.
Can I plant radishes in the fall in Zone 12b?
Zone 12b has no meaningful frost, so the fall and winter months are the easiest time of year to grow radishes here. Sow from about October 1 onward.
Will radishes survive frost in Zone 12b?
Radishes is a hardy crop and keeps going roughly 21 days past the first light frost in Zone 12b. A row cover or a straw mulch buys more.