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When to plant Portulaca in Clinton County County,

Plant Portulaca in Clinton County County from May 7 to May 28 in spring. Clinton County County sits in USDA Zone 6a, with last frost around April 30 and first frost on October 13.

When to Plant Portulaca in Clinton County, MI

Clinton County, Michigan Zone 6a June

June in the garden — Clinton County, Michigan

Each item below is timed to Clinton County, Michigan's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 30
Avg. first frost October 13
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Get portulaca seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

  2. Harvest portulaca as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before July arrives, get these ready
  • 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, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 13, giving you a growing season of approximately 166 days.

At an elevation of 519 feet, Clinton County receives approximately 34.1 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.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Clinton County, MI (Zone 6a) Moderate season
166 days
Last Spring Frost April 30
166 growing days
First Fall Frost October 13

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Start indoors: Mar 23 Transplant: May 4 🌸 Bloom: Jun 22 – Oct 5
Recommended (50%) ✓ Fits season (5 days to spare)
Start indoors: Mar 26 Transplant: May 7 🌸 Bloom: Jun 25 – Oct 8
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: Apr 15 Transplant: May 27 🌸 Bloom: Jul 15 – Oct 28

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 (5.9–6.7) 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.

Drainage

Drainage is adequate for Portulaca.

Organic Matter

Organic matter is excellent (4.8%) — Portulaca will thrive.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

3
successive plantings in your 166-day season

Sow every 5.7 weeks. Last sowing by Aug 04 to harvest before frost.

Portulaca Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2" 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 ~780 GDD — county provides 2,158 GDD Excellent fit

Portulaca Planting Timeline — Clinton County, MI

Portulaca Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Bloom June 25 Jun 25 – Oct 8

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
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 6a

📆 Growing Season

166 days in Clinton County

Growing Tips for Portulaca in Clinton County

Direct sow Portulaca outdoors after April 30 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, MI?

Clinton County is in Zone 6a with an average last frost of April 30. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, MI?

Clinton County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 13.

When should I plant Portulaca in Clinton County County, ?

In Clinton County County, , plant Portulaca after the last frost (around April 30) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Clinton County County, for Portulaca?

Clinton County County sits in USDA Zone 6a. 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 166-day frost-free season, with last frost around April 30 and first frost around October 13.

🌱

Your Clinton County Garden Planner — Free

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

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clinton County, MI. 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.