When to Plant Tomatoes in USDA Zone 3b
June in Zone 3b — your action list
Your garden in Zone 3b is working on a schedule, even when you're not. Here's where you should be this June.
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Transplant tomatoes outside
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
A few tasks this June that'll pay off in July
- Starting indoors: tomatoes
Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.
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.
Tomatoes 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 Tomatoes planting schedule for that location.
Tomatoes Planting Calendar — Zone 3b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 8 | Mar 8 – Mar 22 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | August 2 | Aug 2 – Oct 4 |
Plant 0.5" deep · 24" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| 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.
Growing Conditions
Sun
Full Sun (6-8+ hours)
💧 Water
1.2"/week · Moderate — regular watering
Days to Maturity
60–85 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 Depth | 0.5 inches |
| Plant Spacing | 24 inches apart |
| Row Spacing | 36 inches between rows |
Succession Planting Tomatoes in Zone 3b
Sow every 6.9 weeks for continuous harvest throughout the season.
Recommended Tomatoes Varieties for Zone 3b
Choose early-maturing determinate varieties for your zone's shorter season
Growing Tips for Tomatoes in Zone 3b
Zone 3b has a short growing season (~135 days). Start Tomatoes indoors early and use season-extension techniques like row covers and cold frames.
Tomatoes needs approximately 1.2 inches of water per week during active growth. Adjust watering based on your local rainfall and soil drainage.
Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.
Companion Planting
Good Companions
Avoid Planting Near
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
Saving Tomatoes Seeds
Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type 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
Tomatoes in Other Zones
Tomatoes 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 Tomatoes in Zone 3b?
In Zone 3b, plan your Tomatoes planting around the average last frost date of May 10. Start seeds indoors around March 8. Direct sow outdoors around May 24. Transplant seedlings around May 31.
Can Tomatoes grow in Zone 3b?
Yes, Tomatoes 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 Tomatoes (60-85 days to maturity).
When can I harvest Tomatoes in Zone 3b?
In Zone 3b, expect to harvest Tomatoes from August 2 – October 4. Tomatoes takes 60-85 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 Tomatoes?
Good companion plants for Tomatoes include Basil, Carrots, Parsley, Peppers. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 3b Garden Planner — Free
A 22-page printable planner tailored to Zone 3b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.