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When to Plant Marigolds in Sublette County, WY

Sublette County, Wyoming Zone 4b May

May in Sublette County, Wyoming — your action list

Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 22
Avg. first frost August 24
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Get marigolds seeds going inside

    You're about 3 weeks out from your last frost — the perfect window to get these germinating indoors.

June prep starts now
  • Transplants going out: marigolds
  • Direct-sowing: marigolds

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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.

Sublette County, Wyoming is in USDA Zone 4b. The average last spring frost is June 22 and the first fall frost is August 24, giving you a growing season of approximately 63 days.

At an elevation of 5,005 feet, Sublette County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Marigolds to ensure they mature before fall.

Sublette County, WY (Zone 4b) Very short season
63 days
Last Spring Frost June 22
63 growing days
First Fall Frost August 24
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Sublette County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Jul 29 Transplant: Jun 24 🍅 Harvest: Aug 19 – Nov 4
Recommended (50%) ✗ May not fit
Start indoors: Aug 3 Transplant: Jun 29 🍅 Harvest: Aug 24 – Nov 9
Safe Start (90%) ✗ May not fit
Start indoors: Aug 11 Transplant: Jul 7 🍅 Harvest: Sep 1 – Nov 17

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 Sublette County

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

Soil pH

Your soil pH (6.7–7.8) overlaps with Marigolds's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Marigolds.

How to Plant Marigolds

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.5″/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 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 2.2" 1.5" 0.7" 💧 Light watering
Jul 2.2" 2.2" 0" ✅ Rainfall sufficient
Aug 2.2" 2.1" 0.1" 💧 Light watering
Sep 1.7" 0" ❄️ Dormant
Oct 2" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Sublette 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 ~645 GDD — county provides 677 GDD Good fit

Marigolds Planting Timeline — Sublette County, WY

Marigolds Planting Calendar

Activity When Date Range
Start Indoors August 3 Aug 3 – Aug 17
Transplant Outdoors June 29 Jun 29 – Jul 13
Direct Sow June 29 Jun 29 – Jul 20
Harvest August 24 Aug 24 – Nov 9

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors Direct Sow
July Transplant Outdoors Direct Sow
August Start Indoors Harvest
September Harvest
October Harvest
November Harvest
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: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

63 days in Sublette County

Growing Tips for Marigolds in Sublette County

Direct sow Marigolds outdoors after June 22 in Sublette 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 Sublette County, WY?

Sublette County is in Zone 4b with an average last frost of June 22. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sublette County, WY?

Sublette County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is June 22 and first fall frost is August 24.

🌱

Your Sublette County Garden Planner — Free

A 24-page printable planner built for Sublette County (Zone 4b). 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 Sublette County, WY. 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.