When to Plant Geraniums in USDA Zone 10b
Top priorities for Zone 10b gardeners in June
Your Zone 10b garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Bring in the geraniums
If you can't use it all right away, check the food-preservation section of your planner.
Before July arrives, get these ready
- First harvests: geraniums
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 10b, the average last spring frost is around January 1 and the first fall frost is around December 31, giving you a growing season of approximately 364 days.
Geraniums Planting Timeline — Zone 10b
Where Is USDA Zone 10b?
The map below highlights the states that contain Zone 10b. Click any state to see the Geraniums planting schedule for that location.
Geraniums Planting Calendar — Zone 10b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | October 23 | Oct 23 – Nov 6 |
| Transplant Outdoors | November 13 | Nov 13 – Nov 27 |
| Bloom | January 22 | Jan 22 – Sep 17 |
Plant 0.1" deep · 14" apart · Rows 16" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Bloom |
| February | Bloom |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Start Indoors |
| November | Start Indoors Transplant Outdoors |
| December | — |
Free Zone 10b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 10b 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 40°F average annual minimum
Growing Season
365 days (Zone 10b average)
Planting Specifications
| Planting Depth | 0.1 inches |
| Plant Spacing | 14 inches apart |
| Row Spacing | 16 inches between rows |
Succession Planting Geraniums in Zone 10b
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Geraniums in Zone 10b
Zone 10b offers a long growing season (~365 days). You can plant Geraniums earlier and may get multiple harvests.
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
Good Companions
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
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Saving Geraniums Seeds
Recommended for Your Garden
Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
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 10b?
In Zone 10b, plan your Geraniums planting around the average last frost date of January 1. Start seeds indoors around October 23. Transplant seedlings around November 13.
Can Geraniums grow in Zone 10b?
Yes, Geraniums can grow well in Zone 10b, hardy in USDA zones 2a through 11b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Geraniums (70-100 days to maturity).
When can I harvest Geraniums in Zone 10b?
In Zone 10b, expect to harvest Geraniums from January 22 – September 17. Geraniums takes 70-100 days from planting to harvest.
What is the last frost date for Zone 10b?
The average last spring frost in Zone 10b is around January 1, and the first fall frost is around December 31. This gives a growing season of approximately 364 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 10b Garden Planner — Free
A 22-page printable planner tailored to Zone 10b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.