When to Plant Geraniums in USDA Zone 3b
What to do in June
Your Zone 3b garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
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.
Geraniums 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 Geraniums planting schedule for that location.
Geraniums Planting Calendar — Zone 3b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 22 | Feb 22 – Mar 8 |
| Transplant Outdoors | May 24 | May 24 – Jun 7 |
| Bloom | August 2 | Aug 2 – Sep 27 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Bloom |
| September | Bloom |
| 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.
Growing Conditions
Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
Days to Maturity
70–100 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 | 0.1 inches |
| Plant Spacing | 12 inches apart |
| Row Spacing | 14 inches between rows |
Succession Planting Geraniums in Zone 3b
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Geraniums in Zone 3b
Zone 3b has a short growing season (~135 days). Start Geraniums indoors early and use season-extension techniques like row covers and cold frames.
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
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Saving Geraniums 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
Geraniums in Other Zones
Geraniums 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 Geraniums in Zone 3b?
In Zone 3b, plan your Geraniums planting around the average last frost date of May 10. Start seeds indoors around February 22. Transplant seedlings around May 24.
Can Geraniums grow in Zone 3b?
Yes, Geraniums 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 Geraniums (70-100 days to maturity).
When can I harvest Geraniums in Zone 3b?
In Zone 3b, expect to harvest Geraniums from August 2 – September 27. Geraniums takes 70-100 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 Geraniums?
Good companion plants for Geraniums include Lobelia, Sweet Alyssum, Petunias, Bachelors Button. 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.