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When to plant Lobelia in Gladwin County, MI

Gladwin County sits in cold Zone 6a. Plant Lobelia April 25–May 9 for the single annual harvest; the October 6 first frost closes the window.

When to Plant Lobelia in Gladwin County, MI

Lobelia (Lobelia erinus) is a cool-season annual prized for the intense cobalt blue that is rare among bedding flowers. It blooms most prolifically in spring and early summer but stalls or dies back during heat peaks above 90°F. In zones 3–7 it delivers a long display; in zones 8–9 it is best treated as a spring annual that fades by midsummer. Trailing types cascade beautifully from containers and window boxes.

Gladwin County, Michigan is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 6, giving you a growing season of approximately 150 days.

At an elevation of 832 feet, Gladwin County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Lobelia to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly
Gladwin County, MI (Zone 6a) Moderate season
150 days
Last Spring Frost May 9
150 growing days
First Fall Frost October 6

Gladwin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Lobelia Planting Timeline — Gladwin County, MI

Lobelia Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 25 Apr 25 – May 9
Bloom June 20 Jun 20 – Sep 12

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

150 days in Gladwin County

Growing Tips for Gladwin County

Start seeds indoors 10–12 weeks before last frost — seed is dust-fine and requires light to germinate; surface-sow and press gently. Keep at 65–70°F. Not reliably direct-sown. Transplant in cool weather, 2–4 weeks before last frost date is acceptable in zones 5+. Shear plants by one-third after the first bloom flush to encourage a second flush in fall. Provide afternoon shade in zones 7+ to extend bloom into summer.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lobelia in Gladwin County, MI?

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

What planting zone is Gladwin County, MI?

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

When should I plant Lobelia in Gladwin County, MI?

In Gladwin County, MI, plant Lobelia after the last frost (around May 9) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Gladwin County, MI for Lobelia?

Gladwin County sits in USDA Zone 6a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Gladwin County's climate?

Yes — Lobelia grows well in Gladwin County's temperate climate. Gladwin County averages a 150-day frost-free season, with last frost around May 9 and first frost around October 6.

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Your Gladwin County Garden Planner — Free

A 22-page printable planner built for Gladwin 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.

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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 Gladwin County, MI. Local conditions may vary. Last updated: June 2026.

Sources & credits

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