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When to plant Geraniums in Marquette County County,

Marquette County County's short 163-day growing season means one Geraniums planting between May 17 and May 31. No fall crop in Zone 5a.

When to Plant Geraniums in Marquette County, MI

Marquette County, Michigan Zone 5a June

June in Marquette County, Michigan — your action list

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Marquette County, Michigan.

Avg. last frost May 10
Avg. first frost October 20
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.6 hrs
July will be here before you know it — start on
  • Starting indoors: geraniums
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Marquette County, Michigan is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 20, giving you a growing season of approximately 163 days.

At an elevation of 564 feet, Marquette County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Geraniums to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Marquette County, MI (Zone 5a) Moderate season
163 days
Last Spring Frost May 10
163 growing days
First Fall Frost October 20

Marquette County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Start indoors: Feb 21 Transplant: May 9 🌸 Bloom: Jul 18 – Oct 10
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 1 Transplant: May 17 🌸 Bloom: Jul 26 – Oct 18
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Mar 18 Transplant: Jun 3 🌸 Bloom: Aug 12 – Nov 4

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 Marquette County

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

Soil pH

Your soil pH (6.0–6.8) is within Geraniums's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Geraniums will thrive.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

2
successive plantings in your 163-day season

Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 104 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Geraniums

Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Geraniums Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Geraniums 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.

Geraniums needs ~914 GDD — county provides 1,752 GDD Excellent fit

Geraniums Planting Timeline — Marquette County, MI

Geraniums Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 17 May 17 – May 31
Bloom July 26 Jul 26 – Oct 18

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

163 days in Marquette County

Growing Tips for Geraniums in Marquette County

Direct sow Geraniums outdoors after May 10 in Marquette County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Marquette County, MI?

Marquette County is in Zone 5a with an average last frost of May 10. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marquette County, MI?

Marquette County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 10 and first fall frost is October 20.

When should I plant Geraniums in Marquette County County, ?

In Marquette County County, , plant Geraniums after the last frost (around May 10) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Marquette County County, for Geraniums?

Marquette County County sits in USDA Zone 5a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Marquette County County's climate?

Yes — Geraniums grows well in Marquette County County's temperate climate. Marquette County County averages a 163-day frost-free season, with last frost around May 10 and first frost around October 20.

🌱

Your Marquette County Garden Planner — Free

A 22-page printable planner built for Marquette 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 Marquette County, MI. 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.