Vegetable / Cool season
Radish
The fastest win in the garden, if you pull on time
Plant out byMay 4zone 6
- Family
- Mustard (Brassicaceae)
- Sun
- Part sun (5+ h)
- Difficulty
- Very easy
- Days to harvest
- 21-35 days
- Spacing
- 2 in apart, rows 8 in
- Pot size
- 1 gal pot (great in pots)
- Frost
- Half-hardy
- Start
- Direct sow
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Too late this year (try fall)
In zone 6, sow or plant outdoors Mar 9 to May 4; sow again for fall Sep 8 to Sep 22. Average last frost Apr 20, first fall frost Oct 20.
Units
Radishes are the crop to grow when you need a win. Seed goes in, and three to five weeks later you are pulling round red roots. My kids still treat the first radish of spring as a small holiday, even though neither of them likes eating it.
The catch is timing. Leave them a few days too long and the roots go pithy, woody and fiery hot. Warm weather does the same. That is why spring sowing starts 4 to 6 weeks before your last frost and winds down once days reach about 70 degrees F. Sow a short row every week or two rather than one big batch. Fresh manure or heavy nitrogen also backfires, giving you a pile of leaves on a skinny root.
They fit almost anywhere. Thin seedlings to 1 to 2 inches apart, more for big winter types. Tuck them between slow crops like carrots, since radishes come up first and mark the row. Round varieties grow fine in a shallow pot or window box. Flea beetles chew tiny holes in the leaves, which looks bad but rarely ruins the roots. Root maggots are more serious, and row cover is the simplest fix for both. Keep it on from sowing day. In late summer, sow again 4 to 6 weeks before your first fall frost, when cooler nights bring back crisp, mild roots.
Things to consider
- Compacted or rocky soil gives twisted, extra spicy roots. Loosen the top 6 inches, or about 8 for long types like 'White Icicle'. A raised bed or pot of loose mix skips the problem entirely.
- Uneven watering splits roots and makes them harsher. A heavy soak after a dry spell is the classic trigger, so keep the top few inches evenly moist, above all in a pot.
- Too little light sends the plant's energy into big leaves. Most growers find half a day of sun is about the minimum for decent roots. Under a taller crop, sow at the sunny edge, and pull the radishes before the big plant fills in.
Good neighbours
Pests to watch for
Flea beetlesCabbage root maggotsCutworms
Questions about growing radish
Why are my radishes all leaves and no root?
The usual causes are crowding, rich soil with too much nitrogen, deep shade, or heat. Thinning to proper spacing fixes most cases, painful as it is to pull healthy seedlings. If the weather has turned hot, wait and sow again in late summer. Moving the next row away from fresh compost or manure helps as well.
Can radishes share a row with carrots?
Gardeners often sow them together. Radishes sprout within days, show you where the row is, and get pulled long before the carrots need the room. The same trick works with beets and parsnips, which are also slow to come up. Just pull the radishes on time, or they start crowding the crop they were meant to help.
What are winter radishes?
Larger, slower types such as daikon or black Spanish, sown in mid to late summer. They need more room, at least 2 inches between plants in rows a foot apart. Shortening days are what push them to form big roots, so a spring sowing usually disappoints. They also take far longer, closer to two months than one.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.