When to Plant Portulaca in USDA Zone 10b
August to-do list for Zone 10b
A quick August briefing for Zone 10b gardeners — what's urgent, what's next, and what can wait.
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It's harvest week for portulaca
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Looking ahead to September
- First harvests: portulaca
Portulaca (Portulaca grandiflora), commonly called moss rose, is a succulent- stemmed annual built for hot, dry, low-fertility conditions where other flowers fail. Its silky, rose-like blooms open in full sun and close at night or on cloudy days. Excellent for slopes, rock gardens, containers, and parking-strip plantings where irrigation is limited. One of the easiest annuals for neglect- proof summer color.
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.
Portulaca 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 Portulaca planting schedule for that location.
Portulaca Planting Calendar — Zone 10b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 4 | Dec 4 – Dec 18 |
| Transplant Outdoors | November 20 | Nov 20 – Dec 4 |
| Direct Sow | November 20 | Nov 20 – Dec 11 |
| Bloom | January 8 | Jan 8 – Aug 27 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Bloom |
| February | Bloom |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | Transplant Outdoors Direct Sow |
| December | Start Indoors Transplant Outdoors Direct Sow |
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
Low — drought tolerant
Days to Maturity
50–70 days
Soil pH
5.5 – 7
Zone Temperature Range
35°F to 40°F average annual minimum
Growing Season
365 days (Zone 10b average)
Planting Specifications
| Plant Spacing | 8 inches apart |
| Row Spacing | 10 inches between rows |
Succession Planting Portulaca in Zone 10b
Sow every 5.7 weeks for continuous harvest throughout the season.
Growing Tips for Portulaca in Zone 10b
Zone 10b offers a long growing season (~365 days). You can plant Portulaca earlier and may get multiple harvests.
Direct-sow after last frost once soil warms to 65°F, or start indoors 4–6 weeks before last frost. Seed is tiny — surface sow and do not cover. Thin to proper spacing after germination. Thrives in poor, well-drained soil; rich or wet soil produces lush foliage but fewer blooms. No deadheading required — plants are self-cleaning. Double-flowered varieties hold blooms open longer in overcast conditions.
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
- Bonus: square-foot gardening guide + printable seasonal planners
Saving Portulaca 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
Portulaca in Other Zones
Portulaca 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 Portulaca in Zone 10b?
In Zone 10b, plan your Portulaca planting around the average last frost date of January 1. Start seeds indoors around December 4. Direct sow outdoors around November 20. Transplant seedlings around November 20.
Can Portulaca grow in Zone 10b?
Yes, Portulaca can grow well in Zone 10b, hardy in USDA zones 3a through 11b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Portulaca (50-70 days to maturity).
When can I harvest Portulaca in Zone 10b?
In Zone 10b, expect to harvest Portulaca from January 8 – August 27. Portulaca takes 50-70 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 Portulaca?
Good companion plants for Portulaca include Marigolds, Celosia, Vinca, Zinnias. 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.