When to Plant Portulaca in USDA Zone 5b
Zone 5b gardeners: here's your June plan
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Sow portulaca in trays indoors
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Collect portulaca at their peak
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Looking ahead to July
- 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 5b, the average last spring frost is around April 18 and the first fall frost is around October 13, giving you a growing season of approximately 178 days.
Portulaca Planting Timeline — Zone 5b
Where Is USDA Zone 5b?
The map below highlights the states that contain Zone 5b. Click any state to see the Portulaca planting schedule for that location.
Portulaca Planting Calendar — Zone 5b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 25 | Apr 25 – May 9 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Bloom | June 13 | Jun 13 – Sep 19 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Free Zone 5b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5b 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
-15°F to -10°F average annual minimum
Growing Season
178 days (Zone 5b average)
Planting Specifications
| Plant Spacing | 8 inches apart |
| Row Spacing | 10 inches between rows |
Succession Planting Portulaca in Zone 5b
Sow every 5.7 weeks for continuous harvest throughout the season.
Growing Tips for Portulaca in Zone 5b
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
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 5b?
In Zone 5b, plan your Portulaca planting around the average last frost date of April 18. Start seeds indoors around March 14. Direct sow outdoors around April 25. Transplant seedlings around April 25.
Can Portulaca grow in Zone 5b?
Yes, Portulaca can grow well in Zone 5b, hardy in USDA zones 3a through 11b. Zone 5b has a growing season of approximately 178 days, which is sufficient for Portulaca (50-70 days to maturity).
When can I harvest Portulaca in Zone 5b?
In Zone 5b, expect to harvest Portulaca from June 13 – September 19. Portulaca takes 50-70 days from planting to harvest.
What is the last frost date for Zone 5b?
The average last spring frost in Zone 5b is around April 18, and the first fall frost is around October 13. This gives a growing season of approximately 178 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 5b Garden Planner — Free
A 22-page printable planner tailored to Zone 5b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.