In zone 9, radishes grow best in the cool months. Sow them from fall through late winter: the spring window runs from February 3 to February 17, and the last fall sowing date is about October 14, though in mild winters you can keep sowing. They are ready in about 25–30 days.
Radish dates for your ZIP code
Planting times based on university extension guidance (UNH, Cornell, Purdue, Minnesota, Nebraska and UMass Extension). Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Radish timing in zone 9
| Task | When |
|---|---|
| Sow outside | February 3 – February 17 |
| First harvest | February 28 – March 19 |
| Sow for fall by | October 14 |
| Main season | Fall through early spring |
| Sow again | Every 10–14 days in the cool months |
| Pick | When roots are under 1 inch across |
Most of zone 9 sees its last spring frost between February 16 and March 15 (typical March 3) and its first fall frost between November 15 and December 5 (typical November 25). Radishes tolerate frost and grow fast in cool weather. The tool above uses the weather station closest to your ZIP code.
Why radishes are sown early
Radishes are a fast, cool-season crop that tolerates frost. In cool weather they grow quickly and stay crisp and mild. Heat and slow growth make them hot, pithy and quick to send up seed stalks. That is why they are sown two to four weeks before the last spring frost, and again in late summer.
Best radish varieties for zone 9
In zone 9, radishes are a cool-season crop from fall to spring:
- Spring radishes, round or oval, ready in about a month.
- French Breakfast and Icicle, which handle warmer spells better.
- Winter radishes such as daikon, sown in late summer or fall.
How to plant radishes
- Sow seeds ¼–½ inch deep directly in the garden.
- Thin spring radishes to ½–1 inch apart, and winter radishes to 2–4 inches.
- Sow a short row every 10–14 days for a steady harvest.
- Keep the soil evenly moist so roots grow fast and don’t split.
Zone 9 radish tips
- Grow them through the cool months. Radishes grow fast in cool weather and handle frost.
- Avoid late spring sowings. Radishes maturing in heat turn hot and pithy.
- Water evenly to prevent splitting.
- Harvest young, when roots are under an inch across.
Harvesting radishes
Pull spring radishes when the roots are under about an inch across, usually 25–30 days after sowing. Check them often, because they turn pithy and hot quickly once mature. Remove the greens before storing; radishes keep 5–7 days in the refrigerator. Winter radishes can stay in the garden into fall and keep for months in cold storage.
Radish planting dates in nearby zones
- Zone 8March 3 – March 17
See dates for every zone on the radishes planting guide, or build a full schedule with the planting calendar.
Frequently asked questions
Is it too late to plant radishes in zone 9 in March?
Yes, until fall: heat makes radishes hot and pithy. Start sowing again once the weather cools.
Can I grow radishes in winter in zone 9?
Yes. In mild-winter areas, radishes grow well from fall through early spring.
How long do radishes take to grow?
Spring radishes are ready in about 25–30 days. Winter radishes such as daikon take longer and grow much larger.
Can radishes handle frost?
Yes. Radishes are frost tolerant and are sown two to four weeks before your last spring frost.
Why are my radishes all leaves and no root?
Usually crowding or heat. Thin seedlings to at least ½–1 inch apart, and sow in cool weather.
Sources. Planting dates use the median frost dates of each USDA zone, calculated from NOAA climate data for every ZIP code in the zone.