When to Plant Zucchini in USDA Zone 4b
Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.
In Zone 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.
Zucchini Planting Timeline — Zone 4b
Where Is USDA Zone 4b?
The map below highlights the states that contain Zone 4b. Click any state to see the Zucchini planting schedule for that location.
Zucchini Planting Calendar — Zone 4b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | July 10 | Jul 10 – Sep 4 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 4b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4b with start dates, transplant windows, and harvest times.
Growing Conditions
Sun
Full Sun (6-8+ hours)
💧 Water
1.2"/week · Moderate — regular watering
Days to Maturity
45–60 days
Soil pH
6 – 7.5
Zone Temperature Range
-25°F to -20°F average annual minimum
Growing Season
155 days (Zone 4b average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 30 inches apart |
| Row Spacing | 42 inches between rows |
Succession Planting Zucchini in Zone 4b
Sow every 5.1 weeks for continuous harvest throughout the season.
Growing Tips for Zucchini in Zone 4b
Zone 4b has a short growing season (~155 days). Start Zucchini indoors early and use season-extension techniques like row covers and cold frames.
Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Saving Zucchini Seeds
Recommended for Your Garden
Full-spectrum LED lights for starting seeds indoors when daylight is limited.
Warm soil for faster germination of heat-loving crops like tomatoes and peppers.
Protect plants from frost, wind, and pests while letting light and water through.
Related Plants
Zucchini in Other Zones
Zucchini by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Zucchini in Zone 4b?
In Zone 4b, plan your Zucchini planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around May 15. Transplant seedlings around May 22.
Can Zucchini grow in Zone 4b?
Yes, Zucchini can grow well in Zone 4b, hardy in USDA zones 3a through 11b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Zucchini (45-60 days to maturity).
When can I harvest Zucchini in Zone 4b?
In Zone 4b, expect to harvest Zucchini from July 10 – September 4. Zucchini takes 45-60 days from planting to harvest.
What is the last frost date for Zone 4b?
The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 days. These are 50% probability dates — actual frost dates vary year to year.
What should I plant next to Zucchini?
Good companion plants for Zucchini include Corn, Green Beans, Basil, Borage. 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 4b, track your crops, and plan your garden season from seed to harvest.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.