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When to Plant Marigolds in Ozaukee County, WI

Ozaukee County, Wisconsin Zone 5b May

May to-do list for Ozaukee County, Wisconsin

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Ozaukee County, Wisconsin.

Avg. last frost April 27
Avg. first frost October 11
Soil temp (4") 56°F
Watering Moderate
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. Sow marigolds where they'll grow

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

To set up a strong June, finish these tasks
  • First harvests: 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.

Ozaukee County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 11, giving you a growing season of approximately 167 days.

At an elevation of 1,277 feet, Ozaukee County receives approximately 32.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Marigolds to ensure they mature before fall.

Ozaukee County, WI (Zone 5b) Moderate season
167 days
Last Spring Frost April 27
167 growing days
First Fall Frost October 11

Ozaukee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Jun 5 Transplant: May 1 🍅 Harvest: Jun 26 – Sep 25
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Jun 8 Transplant: May 4 🍅 Harvest: Jun 29 – Sep 28
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Jun 24 Transplant: May 20 🍅 Harvest: Jul 15 – Oct 14

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 Ozaukee County

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

Soil pH

Your soil pH (6.1–7.1) is within Marigolds's preferred range (6.0–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Marigolds.

Organic Matter

Organic matter is excellent (4.7%) — Marigolds will thrive.

How to Plant Marigolds

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

Succession Planting Marigolds

3
successive plantings in your 167-day season

Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.

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 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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 3.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.5" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ozaukee 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 ~780 GDD — county provides 2,171 GDD Excellent fit

Marigolds Planting Timeline — Ozaukee County, WI

Marigolds Planting Calendar

Activity When Date Range
Start Indoors June 8 Jun 8 – Jun 22
Transplant Outdoors May 4 May 4 – May 18
Direct Sow May 4 May 4 – May 25
Harvest June 29 Jun 29 – Sep 28

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 Harvest
July Harvest
August Harvest
September Harvest
October
November
December

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: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

167 days in Ozaukee County

Growing Tips for Marigolds in Ozaukee County

Direct sow Marigolds outdoors after April 27 in Ozaukee 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 Ozaukee County, WI?

Ozaukee County is in Zone 5b with an average last frost of April 27. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ozaukee County, WI?

Ozaukee County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 11.

🌱

Your Ozaukee County Garden Planner — Free

A 24-page printable planner built for Ozaukee County (Zone 5b). 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 Ozaukee County, WI. 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.