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When to plant Asparagus in Jefferson County, IL

In Jefferson County, Asparagus is a single-season spring crop — there's no second fall window. Plant April 23–May 7 for an 730–1095-day harvest, finishing well before the October 20 first frost.

When to Plant Asparagus in Jefferson County, IL

Asparagus

Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.

Jefferson County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 509 feet, Jefferson County receives approximately 34 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Asparagus during the growing season.

Jefferson County, IL (Zone 6b) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Asparagus Planting Timeline — Jefferson County, IL

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Jefferson County

Growing Tips for Jefferson County

Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.

Companion Planting

Good Companions

Avoid Planting Near

  • Garlic
  • Onion

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Asparagus in Jefferson County, IL?

Jefferson County is in Zone 6b with an average last frost of April 9. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, IL?

Jefferson County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 20.

When should I plant Asparagus in Jefferson County, IL?

In Jefferson County, IL, plant Asparagus after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Jefferson County, IL for Asparagus?

Jefferson County sits in USDA Zone 6b. Asparagus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Asparagus grow in Jefferson County's climate?

Yes — Asparagus grows well in Jefferson County's temperate climate. Jefferson County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

🌱

Your Jefferson County Garden Planner — Free

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

Sources & credits

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