Blog

When to plant Marigolds in Mahnomen County, MN

Mahnomen County's 137-day season only supports one Marigolds planting per year. Sow between May 27 and June 17 for the best chance at full maturity before September 27.

When to Plant Marigolds in Mahnomen County, MN

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.

Mahnomen County, Minnesota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 27, giving you a growing season of approximately 137 days.

At an elevation of 1,223 feet, Mahnomen County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Marigolds to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Mahnomen County, MN (Zone 4a) Short season
137 days
Last Spring Frost May 13
137 growing days
First Fall Frost September 27

Mahnomen County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Marigolds Planting Timeline — Mahnomen County, MN

Marigolds Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 27 May 27 – Jun 17
Bloom July 22 Jul 22 – Oct 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

137 days in Mahnomen County

Growing Tips for Mahnomen County

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 Mahnomen County, MN?

Mahnomen County is in Zone 4a with an average last frost of May 13. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mahnomen County, MN?

Mahnomen County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 27.

When should I plant Marigolds in Mahnomen County, MN?

In Mahnomen County, MN, plant Marigolds after the last frost (around May 13) and before the first frost (around September 27). Best results when soil holds above 50°F.

What growing zone is Mahnomen County, MN for Marigolds?

Mahnomen County sits in USDA Zone 4a. Marigolds grows reliably in zones 2a through 11b, so it's a good fit here.

Can Marigolds grow in Mahnomen County's climate?

Yes — Marigolds grows well in Mahnomen County's temperate climate. Mahnomen County averages a 137-day frost-free season, with last frost around May 13 and first frost around September 27.

🌱

Your Mahnomen County Garden Planner — Free

A 22-page printable planner built for Mahnomen County (Zone 4a). 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 Mahnomen County, MN. 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.