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When to plant Alliums in Monroe County, MI

Spring Alliums in Monroe County goes in mid-spring–late spring, once nighttime temps stop dipping near freezing. A second sowing from September 5 to September 19 extends the harvest into fall.

When to Plant Alliums in Monroe County, MI

Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.

Monroe County, Michigan is in USDA Zone 6b. The average last spring frost is April 27 and the first fall frost is October 17, giving you a growing season of approximately 173 days.

At an elevation of 1,202 feet, Monroe County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Alliums during the growing season.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Monroe County, MI (Zone 6b) Moderate season
173 days
Last Spring Frost April 27
173 growing days
First Fall Frost October 17

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Alliums Planting Timeline — Monroe County, MI

Alliums Planting Calendar

Activity When Date Range
Bloom October 3 Oct 3 – Oct 31
Fall Sowing September 5 Sep 5 – Sep 19

Plant 5" deep · 7" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September Fall Sowing
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

28–42 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

173 days in Monroe County

Growing Tips for Monroe County

Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Peas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alliums in Monroe County, MI?

Monroe County is in Zone 6b with an average last frost of April 27. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, MI?

Monroe County, Michigan is in USDA Hardiness Zone 6b. The average last spring frost is April 27 and first fall frost is October 17.

When should I plant Alliums in Monroe County, MI?

In Monroe County, MI, plant Alliums after the last frost (around April 27) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Monroe County, MI for Alliums?

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

Can Alliums grow in Monroe County's climate?

Yes — Alliums grows well in Monroe County's temperate climate. Monroe County averages a 173-day frost-free season, with last frost around April 27 and first frost around October 17.

🌱

Your Monroe County Garden Planner — Free

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

Sources & credits

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