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When to plant Portulaca in Clinton County County,

Clinton County County's spring Portulaca window runs April 17 through May 8. time plantings around the expected last-frost window for best survival.

When to Plant Portulaca in Clinton County, IL

Clinton County, Illinois Zone 6b June

June to-do list for Clinton County, Illinois

Your Clinton County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Basket week: portulaca

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in July — start thinking about
  • First harvests: portulaca

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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.

Clinton County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 1,142 feet, Clinton County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Portulaca during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Clinton County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Feb 28 Transplant: Apr 11 🌸 Bloom: May 30 – Sep 19
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 6 Transplant: Apr 17 🌸 Bloom: Jun 5 – Sep 25
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Mar 15 Transplant: Apr 26 🌸 Bloom: Jun 14 – Oct 4

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 Clinton County

How your county's soil matches Portulaca's growing requirements.

Soil pH

Your soil pH (6.0–7.0) is within Portulaca's preferred range (5.5–7.0).

Soil Texture

The silt loam soil in Clinton County is excellent for Portulaca — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.5%) — Portulaca will thrive.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

4
successive plantings in your 192-day season

Sow every 5.7 weeks. Last sowing by Aug 10 to harvest before frost.

Portulaca Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.2" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clinton 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 needs ~825 GDD — county provides 2,640 GDD Excellent fit

Portulaca Planting Timeline — Clinton County, IL

Portulaca Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 17 Apr 17 – May 8
Bloom June 5 Jun 5 – Sep 25

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
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 6b

📆 Growing Season

192 days in Clinton County

Growing Tips for Portulaca in Clinton County

Direct sow Portulaca outdoors after April 10 in Clinton 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 →

Frequently Asked Questions

When should I plant Portulaca in Clinton County, IL?

Clinton County is in Zone 6b with an average last frost of April 10. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, IL?

Clinton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

When should I plant Portulaca in Clinton County County, ?

In Clinton County County, , plant Portulaca after the last frost (around April 10) and before the first frost (around October 19). Best results when soil holds above 50°F.

What growing zone is Clinton County County, for Portulaca?

Clinton County County sits in USDA Zone 6b. Portulaca grows reliably in zones 3a through 11b, so it's a good fit here.

Can Portulaca grow in Clinton County County's climate?

Yes — Portulaca grows well in Clinton County County's temperate climate. Clinton County County averages a 192-day frost-free season, with last frost around April 10 and first frost around October 19.

🌱

Your Clinton County Garden Planner — Free

A 22-page printable planner built for Clinton County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clinton County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.