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When to Plant Purslane in Sullivan County, IN

Sullivan County, Indiana Zone 6b May

This month in Sullivan County, Indiana

We've pulled the most time-sensitive tasks for Sullivan County, Indiana this May and put them front and centre. Tackle them in order.

Avg. last frost April 18
Avg. first frost October 17
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Get purslane seeds going inside

    These need a head start before your last frost (April 18). Sow into cells now so you're ready to transplant in a few weeks.

  2. Harvest purslane as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of June
  • First harvests: purslane

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Purslane is a succulent edible plant rich in omega-3 fatty acids, often considered a weed but increasingly valued as a nutritious green. It has a lemony, peppery flavor.

Sullivan County, Indiana is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 17, giving you a growing season of approximately 182 days.

At an elevation of 914 feet, Sullivan County receives approximately 34.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Purslane during the growing season.

Sullivan County, IN (Zone 6b) Moderate season
182 days
Last Spring Frost April 18
182 growing days
First Fall Frost October 17
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Sullivan County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: May 25 – Jun 29
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (102 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 15 – Jul 20

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 Sullivan County

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

Soil pH

Your soil pH (6.0–7.0) is within Purslane's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

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

How to Plant Purslane

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Purslane

5
successive plantings in your 182-day season

Sow every 4.6 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

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

Monthly Watering Guide for Purslane

Purslane 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 Purslane Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 3.5" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sullivan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Purslane 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.

Purslane needs ~875 GDD — county provides 3,185 GDD Excellent fit

Purslane Planting Timeline — Sullivan County, IN

Purslane Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest May 30 May 30 – Jul 4
Fall Sowing August 8 Aug 8 – Aug 22

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July Harvest
August Fall Sowing
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

182 days in Sullivan County

Growing Tips for Purslane in Sullivan County

Direct sow Purslane outdoors after April 18 in Sullivan County when soil has warmed and frost danger has passed.

Your generous 182.0-day season in Sullivan County allows multiple plantings of Purslane. Sow every 20.0 days for continuous harvest.

General growing tips

Direct sow after last frost or allow to self-seed. Purslane thrives in hot, dry conditions. Harvest stem tips regularly. Contains more omega-3 fatty acids than any other leafy green.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Purslane in Sullivan County, IN?

Sullivan County is in Zone 6b with an average last frost of April 18. Plan your Purslane planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sullivan County, IN?

Sullivan County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 17.

🌱

Your Sullivan County Garden Planner — Free

A 24-page printable planner built for Sullivan 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 Sullivan County, IN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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