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When to plant Garlic in Sullivan County, MO

Plant Garlic in Sullivan County from mid-spring to late spring in spring. Sullivan County sits in USDA Zone 6a, with last frost around April 17 and first frost on October 17. A second sowing from September 5 to September 19 extends the harvest into fall.

When to Plant Garlic in Sullivan County, MO

Garlic

Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Sullivan County, Missouri is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 1,019 feet, Sullivan County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Garlic to ensure they mature before fall.

Sullivan County, MO (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

Sullivan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Garlic Planting Timeline — Sullivan County, MO

Garlic Planting Calendar

Activity When Date Range
Harvest December 5 Dec 5 – Mar 20
Fall Sowing September 5 Sep 5 – Sep 19

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in Sullivan County

Growing Tips for Sullivan County

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Sullivan County, MO?

Sullivan County is in Zone 6a with an average last frost of April 17. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sullivan County, MO?

Sullivan County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.

When should I plant Garlic in Sullivan County, MO?

In Sullivan County, MO, plant Garlic after the last frost (around April 17) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Sullivan County, MO for Garlic?

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

Can Garlic grow in Sullivan County's climate?

Yes — Garlic grows well in Sullivan County's temperate climate. Sullivan County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.

🌱

Your Sullivan County Garden Planner — Free

A 22-page printable planner built for Sullivan 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 Sullivan County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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