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When to Plant Marigolds in Windsor County, VT

Windsor County, Vermont Zone 5a May

Your May gardening checklist

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 12
Avg. first frost October 7
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant marigolds

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter marigolds into prepared beds

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Windsor County, Vermont is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 7, giving you a growing season of approximately 148 days.

At an elevation of 309 feet, Windsor County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Marigolds to ensure they mature before fall.

Windsor County, VT (Zone 5a) Short season
148 days
Last Spring Frost May 12
148 growing days
First Fall Frost October 7
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Windsor County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Jun 17 Transplant: May 13 🍅 Harvest: Jul 8 – Sep 30
Recommended (50%) ✓ Fits season (1 days to spare)
Start indoors: Jun 23 Transplant: May 19 🍅 Harvest: Jul 14 – Oct 6
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: Jul 6 Transplant: Jun 1 🍅 Harvest: Jul 27 – Oct 19

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 Windsor County

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

Soil pH

Your soil pH (4.9–6.5) is more acidic than Marigolds prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Marigolds.

How to Plant Marigolds

0.3"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Marigolds

3
successive plantings in your 148-day season

Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Marigolds

Marigolds 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 Marigolds Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4.6" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 2.2" 4.5" 0" ✅ Rainfall sufficient
Nov 3.5" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

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

Marigolds 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.

Marigolds needs ~735 GDD — county provides 1,813 GDD Excellent fit

Marigolds Planting Timeline — Windsor County, VT

Marigolds Planting Calendar

Activity When Date Range
Start Indoors June 23 Jun 23 – Jul 7
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 19 May 19 – Jun 9
Harvest July 14 Jul 14 – Oct 6

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

148 days in Windsor County

Growing Tips for Marigolds in Windsor County

Direct sow Marigolds outdoors after May 12 in Windsor County when soil has warmed and frost danger has passed.

Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

Frequently Asked Questions

When should I plant Marigolds in Windsor County, VT?

Windsor County is in Zone 5a with an average last frost of May 12. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Windsor County, VT?

Windsor County, Vermont is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 7.

🌱

Your Windsor County Garden Planner — Free

A 24-page printable planner built for Windsor 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 Windsor 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.