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When to Plant Radish in USDA Zone 3b

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Radish Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Radish planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Radish Planting Calendar — Zone 3b

Activity When Date Range
Direct Sow May 3 May 3 – May 24
Harvest May 31 May 31 – Jun 21
Fall Sowing June 30 Jun 30 – Jul 14

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow Harvest
June Fall Sowing Harvest
July Fall Sowing
August
September
October
November
December

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Moderate — regular watering

Days to Maturity

22–35 days

Soil pH

6 – 7

Zone Temperature Range

-35°F to -30°F average annual minimum

Growing Season

135 days (Zone 3b average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing2 inches apart
Row Spacing6 inches between rows

Succession Planting Radish in Zone 3b

7
successive plantings in Zone 3b's ~135-day season

Sow every 2.4 weeks for continuous harvest throughout the season.

Growing Tips for Radish in Zone 3b

Zone 3b has a short growing season (~135 days). Start Radish indoors early and use season-extension techniques like row covers and cold frames.

Radish needs approximately 0.5 inches of water per week during active growth. Adjust watering based on your local rainfall and soil drainage.

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Level Up Your Garden

Saving Radish Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Related Plants

Frequently Asked Questions

When should I plant Radish in Zone 3b?

In Zone 3b, plan your Radish planting around the average last frost date of May 10. Direct sow outdoors around May 3.

Can Radish grow in Zone 3b?

Yes, Radish can grow well in Zone 3b, hardy in USDA zones 2a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Radish (22-35 days to maturity).

When can I harvest Radish in Zone 3b?

In Zone 3b, expect to harvest Radish from May 31 – June 21. Radish takes 22-35 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Radish?

Good companion plants for Radish include Carrots, Lettuce, Peas, Spinach. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 3b, track your crops, and plan your garden season from seed to harvest.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.