Blog

When to plant Geraniums in Ottawa County, MI

Ottawa County sits in cold Zone 6a. Plant Geraniums May 16–May 30 for the single annual harvest; the October 9 first frost closes the window.

When to Plant Geraniums in Ottawa County, MI

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.

Ottawa County, Michigan is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 9, giving you a growing season of approximately 153 days.

At an elevation of 1,027 feet, Ottawa County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°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
Ottawa County, MI (Zone 6a) Moderate season
153 days
Last Spring Frost May 9
153 growing days
First Fall Frost October 9

Ottawa County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Geraniums Planting Timeline — Ottawa County, MI

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors May 16 May 16 – May 30
Bloom July 25 Jul 25 – Oct 24

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
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

Moderate — regular watering

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

153 days in Ottawa County

Growing Tips for Ottawa County

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 Ottawa County, MI?

Ottawa County is in Zone 6a with an average last frost of May 9. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ottawa County, MI?

Ottawa County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 9.

When should I plant Geraniums in Ottawa County, MI?

In Ottawa County, MI, plant Geraniums after the last frost (around May 9) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Ottawa County, MI for Geraniums?

Ottawa County sits in USDA Zone 6a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Ottawa County's climate?

Yes — Geraniums grows well in Ottawa County's temperate climate. Ottawa County averages a 153-day frost-free season, with last frost around May 9 and first frost around October 9.

🌱

Your Ottawa County Garden Planner — Free

A 22-page printable planner built for Ottawa County (Zone 6a). 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 Ottawa County, MI. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.