Plant Radishes in Zone 6a
Seed-starting, transplant & harvest dates for USDA Zone 6a
Zone 6a averages 176 frost-free days, running from a last spring frost around April 20 to a first fall frost around October 13. Radishes needs roughly 28 days from planting out to first harvest, so it uses about 16 percent of that window. Radishes is a hardy crop, which is what decides where in the window it belongs.
Radishes handles cold soil, so there is no reason to wait for the frost date. Direct sow around Mar 23, roughly 4 weeks before the Zone 6a last frost, as soon as the ground is workable. Sowing at the last frost instead costs you the coolest and best part of the season. At 28 days to harvest, a 176-day Zone 6a season has room for about 4 sowings, so stagger them rather than planting everything at once.
Planting radishes for a fall harvest in Zone 6a
Yes. Sow radishes by September 22 in Zone 6a. That is 21 days before the average first frost, which covers the 28 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 21 days radishes keeps going once light frost arrives.
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 6a 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 6a
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Mar 23 | Mar 23 | Apr 20 |
| Fall | by Sep 22 | Sep 22 | Oct 20 |
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 6a
Frequently asked questions
When should I start radishes in Zone 6a?
Direct sow outdoors around Mar 23.
Can I direct sow radishes in Zone 6a?
Yes, direct sow around Mar 23.
Can I plant radishes in the fall in Zone 6a?
Yes. Sow radishes by September 22 in Zone 6a. That is 21 days before the average first frost, which covers the 28 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 21 days radishes keeps going once light frost arrives.
Will radishes survive frost in Zone 6a?
Radishes is a hardy crop and keeps going roughly 21 days past the first light frost in Zone 6a. A row cover or a straw mulch buys more.
How many plantings of radishes fit in a Zone 6a season?
About 4. Zone 6a averages 176 frost-free days and radishes needs roughly 28 days plus a couple of weeks of turnaround, so sowing every 21 days keeps a supply coming.