When to plant Portulaca in McHenry County, IL
McHenry County's spring Portulaca window runs April 25 through May 16. time plantings around the expected last-frost window for best survival.
When to Plant Portulaca in McHenry County, IL
July in the garden — McHenry County, Illinois
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in McHenry County, Illinois.
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Start harvesting portulaca
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Before August arrives, get these ready
- 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.
McHenry County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.
At an elevation of 640 feet, McHenry County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Portulaca to ensure they mature before fall.
McHenry County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
Drainage
Well Drained
Portulaca Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in McHenry County
How your county's soil matches Portulaca's growing requirements.
Soil pH
Your soil pH (5.9–6.7) is within Portulaca's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in McHenry County is excellent for Portulaca — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Portulaca will thrive.
How to Plant Portulaca
Succession Planting Portulaca
Sow every 5.7 weeks. Last sowing by Aug 11 to harvest before frost.
Portulaca Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Portulaca
Portulaca needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Portulaca Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in McHenry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Portulaca Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Portulaca Planting Timeline — McHenry County, IL
Portulaca Planting Calendar
| 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 | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
185 days in McHenry County
Growing Tips for Portulaca in McHenry County
Direct sow Portulaca outdoors after April 18 in McHenry County when soil has warmed and frost danger has passed.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Portulaca in Other Locations
Frequently Asked Questions
When should I plant Portulaca in McHenry County, IL?
McHenry County is in Zone 5b with an average last frost of April 18. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.
What planting zone is McHenry County, IL?
McHenry County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 20.
When should I plant Portulaca in McHenry County, IL?
In McHenry County, IL, plant Portulaca after the last frost (around April 18) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is McHenry County, IL for Portulaca?
McHenry County sits in USDA Zone 5b. Portulaca grows reliably in zones 3a through 11b, so it's a good fit here.
Can Portulaca grow in McHenry County's climate?
Yes — Portulaca grows well in McHenry County's temperate climate. McHenry County averages a 185-day frost-free season, with last frost around April 18 and first frost around October 20.
Your McHenry County Garden Planner — Free
A 22-page printable planner built for McHenry County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.