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When to plant Alliums in Otter Tail County, MN

The best window to plant Alliums in Otter Tail County, is mid-spring–late spring, when soil warms to 50°F. Last frost typically hits May 11; first frost September 28. A second sowing from August 17 to August 31 extends the harvest into fall.

When to Plant Alliums in Otter Tail County, MN

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.

Otter Tail County, Minnesota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 28, giving you a growing season of approximately 140 days.

At an elevation of 571 feet, Otter Tail County receives approximately 40.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Alliums to ensure they mature before fall.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Otter Tail County, MN (Zone 4a) Short season
140 days
Last Spring Frost May 11
140 growing days
First Fall Frost September 28

Otter Tail County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Alliums Planting Timeline — Otter Tail County, MN

Alliums Planting Calendar

Activity When Date Range
Bloom September 28 Sep 28 – Oct 19
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Fall Sowing
September Bloom
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 4a

📆 Growing Season

140 days in Otter Tail County

Growing Tips for Otter Tail 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 Otter Tail County, MN?

Otter Tail County is in Zone 4a with an average last frost of May 11. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Otter Tail County, MN?

Otter Tail County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 28.

When should I plant Alliums in Otter Tail County, MN?

In Otter Tail County, MN, plant Alliums after the last frost (around May 11) and before the first frost (around September 28). Best results when soil holds above 50°F.

What growing zone is Otter Tail County, MN for Alliums?

Otter Tail County sits in USDA Zone 4a. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.

Can Alliums grow in Otter Tail County's climate?

Yes — Alliums grows well in Otter Tail County's temperate climate. Otter Tail County averages a 140-day frost-free season, with last frost around May 11 and first frost around September 28.

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Your Otter Tail County Garden Planner — Free

A 22-page printable planner built for Otter Tail County (Zone 4a). 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 Otter Tail County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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