When to Plant Radishes
Planting Window
- Direct sow
- Several weeks before last frost
| USDA Zone | Typical Window |
|---|---|
| Zone 5 and colder | April, with several successive sowings |
| Zone 6-7 | As early as March |
| Zone 8 and south | Fall, winter, and early spring |
Radishes are the fastest crop on this entire site by a wide margin, commonly reaching harvest in as little as three to four weeks - a speed that changes the whole planning logic compared to slower root crops like carrots or parsnips grown in the same bed.
Direct Sowing, Very Early
Radishes tolerate an early start better than almost anything else here - seed goes into workable early spring soil even a few weeks ahead of your last frost date, since radishes are genuinely frost-tolerant and their extremely short maturity window leaves little exposure time for a late cold snap to do real damage.
Winter Storage Radishes Run on a Different Calendar
Daikon and watermelon radish varieties are a genuinely different planting case from quick spring radishes - they're sown in mid-to-late summer for a fall harvest, take considerably longer to mature (often 50-60 days rather than three to four weeks), and produce large roots meant to be stored through winter rather than eaten within days of pulling.
Succession Sowing Every Week or Two
Because a single planting matures and passes its peak within roughly a week's window, sowing a small new row every seven to ten days through the cool part of the season - rather than one larger planting - is the standard way to keep a continuous supply rather than a single short glut followed by nothing.
A Genuine Trap Crop for Flea Beetles
Radishes are sometimes deliberately interplanted with slower brassicas specifically because flea beetles, a common early-season pest of young cabbage-family seedlings, show a strong preference for radish foliage - a documented enough effect that radishes are one of the better-evidenced trap crops in the companion-planting world, alongside nasturtium's aphid role covered elsewhere on this site.
A Bolted Radish Isn't Necessarily Wasted
A radish plant left to bolt and flower produces edible seed pods - crisp, peppery, and harvested young while still tender - a genuine bonus crop some gardeners deliberately let a late planting run to, rather than treating a bolted radish purely as a wasted planting.
Zone boundaries follow the USDA Plant Hardiness Zone Map (2023 revision); frost windows reflect NOAA/NCEI climate normals. Both are typical historical ranges, reviewed annually - not a forecast or a guarantee for any single year. See Methodology & Sources.
Frequently Asked Questions
Why did my radishes turn woody and overly spicy this time even though they grew fine earlier in the season?
That's almost always heat-driven - radishes left in the ground too long, or grown as temperatures climb into summer, get tougher and noticeably more pungent than the same variety grown in cool spring or fall conditions, which is why timing matters more for radishes than for most root vegetables.
Can I keep sowing radishes all summer long?
In most zones, no - summer heat consistently pushes radishes toward bolting and poor, overly pungent root quality regardless of how frequently you sow fresh seed, so most experienced gardeners deliberately pause radish sowing through the hottest stretch of the year and resume once temperatures cool again in late summer or early fall.
How long do daikon and watermelon radishes actually keep compared to a quick spring radish?
Considerably longer - a spring radish is best used within a week or two of pulling and turns soft and hollow fairly quickly after that, while a properly cured daikon or watermelon radish can hold for a couple of months in a cold, humid spot like a root cellar or the crisper drawer, closer to how a turnip or beet stores than how a quick spring radish does.