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When to Plant Cucumber in USDA Zone 3b

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

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

Cucumber 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 Cucumber planting schedule for that location.

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

Cucumber Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest July 26 Jul 26 – Sep 20

Plant 0.5" deep · 24" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
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

High — keep soil consistently moist

Days to Maturity

50–70 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 Spacing24 inches apart
Row Spacing48 inches between rows

Growing Tips for Zone 3b

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Level Up Your Garden

Saving Cucumber Seeds

Recommended for Your Garden

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LED Grow Lights $25-60

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

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Seedling Heat Mat $15-35

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

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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 Cucumber in Zone 3b?

In Zone 3b, plan your Cucumber planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 24. Transplant seedlings around May 31.

Can Cucumber grow in Zone 3b?

Yes, Cucumber can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Cucumber (50-70 days to maturity).

When can I harvest Cucumber in Zone 3b?

In Zone 3b, expect to harvest Cucumber from July 26 – September 20. Cucumber takes 50-70 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 Cucumber?

Good companion plants for Cucumber include Corn, Peas, Radish, Sunflower. 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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Free download. Plan your entire garden season in minutes.

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.