When to Plant Portulaca in USDA Zone 5a
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 5a, the average last spring frost is around April 25 and the first fall frost is around October 8, giving you a growing season of approximately 166 days.
Portulaca Planting Timeline — Zone 5a
Where Is USDA Zone 5a?
The map below highlights the states that contain Zone 5a. Click any state to see the Portulaca planting schedule for that location.
Portulaca Planting Calendar — Zone 5a
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 9 | May 9 – May 30 |
| Bloom | June 27 | Jun 27 – Sep 26 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Free Zone 5a Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5a 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
-20°F to -15°F average annual minimum
Growing Season
166 days (Zone 5a average)
Planting Specifications
| Plant Spacing | 8 inches apart |
| Row Spacing | 10 inches between rows |
Succession Planting Portulaca in Zone 5a
Sow every 5.7 weeks for continuous harvest throughout the season.
Growing Tips for Portulaca in Zone 5a
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
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Saving Portulaca Seeds
Recommended for Your Garden
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Keep your garden organized with durable, weather-resistant plant labels.
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 5a?
In Zone 5a, plan your Portulaca planting around the average last frost date of April 25. Start seeds indoors around March 21. Direct sow outdoors around May 9. Transplant seedlings around May 9.
Can Portulaca grow in Zone 5a?
Yes, Portulaca can grow well in Zone 5a, hardy in USDA zones 3a through 11b. Zone 5a has a growing season of approximately 166 days, which is sufficient for Portulaca (50-70 days to maturity).
When can I harvest Portulaca in Zone 5a?
In Zone 5a, expect to harvest Portulaca from June 27 – September 26. Portulaca takes 50-70 days from planting to harvest.
What is the last frost date for Zone 5a?
The average last spring frost in Zone 5a is around April 25, and the first fall frost is around October 8. This gives a growing season of approximately 166 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 5a Garden Planner — Free
A 22-page printable planner tailored to Zone 5a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.