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When to Plant Purslane in Grand Isle County, VT

Grand Isle County, Vermont Zone 5a May

This month in Grand Isle County, Vermont

Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 6
Avg. first frost October 10
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Transplant purslane outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

Coming up in June — start thinking about
  • Starting indoors: purslane
  • 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.

Grand Isle County, Vermont is in USDA Zone 5a. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.

At an elevation of 1,011 feet, Grand Isle County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Purslane to ensure they mature before fall.

Grand Isle County, VT (Zone 5a) Moderate season
157 days
Last Spring Frost May 6
157 growing days
First Fall Frost October 10
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Grand Isle County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 11 – Jul 16
Recommended (50%) ✓ Fits season (80 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jun 28 – Aug 2

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 Grand Isle County

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

Soil pH

Your soil pH (4.8–6.4) overlaps with Purslane's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Purslane.

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

4
successive plantings in your 157-day season

Sow every 4.6 weeks. Last sowing by Aug 11 to harvest before frost.

For a dedicated fall crop, sow by Aug 01.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 2.5" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 3.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Grand Isle 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 ~650 GDD — county provides 2,041 GDD Excellent fit

Purslane Planting Timeline — Grand Isle County, VT

Purslane Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 22 Apr 22 – May 13
Harvest June 17 Jun 17 – Jul 22
Fall Sowing August 1 Aug 1 – Aug 15

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
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: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

157 days in Grand Isle County

Growing Tips for Purslane in Grand Isle County

Direct sow Purslane outdoors after May 06 in Grand Isle County when soil has warmed and frost danger has passed.

Your generous 157.0-day season in Grand Isle 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 Grand Isle County, VT?

Grand Isle County is in Zone 5a with an average last frost of May 6. Plan your Purslane planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grand Isle County, VT?

Grand Isle County, Vermont is in USDA Hardiness Zone 5a. The average last spring frost is May 6 and first fall frost is October 10.

🌱

Your Grand Isle County Garden Planner — Free

A 24-page printable planner built for Grand Isle County (Zone 5a). 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 Grand Isle County, VT. 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.