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When to plant Asparagus in St. Clair County County,

St. Clair County County's 214-day season only supports one Asparagus planting per year. Sow between April 16 and April 30 for the best chance at full maturity before November 2.

When to Plant Asparagus in St. Clair 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.

St. Clair County, Illinois is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is November 2, giving you a growing season of approximately 214 days.

At an elevation of 711 feet, St. Clair County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Asparagus during the growing season.

St. Clair County, IL (Zone 7a) Long season
214 days
Last Spring Frost April 2
214 growing days
First Fall Frost November 2
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St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Monthly Watering Guide for Asparagus

Asparagus needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Asparagus Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 4.3" 2.4" 1.9" 💧 Light watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Asparagus Planting Timeline — St. Clair County, IL

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors April 16 Apr 16 – Apr 30

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June
July
August
September
October
November
December
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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 7a

📆 Growing Season

214 days in St. Clair County

Growing Tips for St. Clair 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 St. Clair County, IL?

St. Clair County is in Zone 7a with an average last frost of April 2. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Clair County, IL?

St. Clair County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is November 2.

When should I plant Asparagus in St. Clair County County, ?

In St. Clair County County, , plant Asparagus after the last frost (around April 2) and before the first frost (around November 2). Best results when soil holds above 50°F.

What growing zone is St. Clair County County, for Asparagus?

St. Clair County County sits in USDA Zone 7a. Asparagus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Asparagus grow in St. Clair County County's climate?

Yes — Asparagus grows well in St. Clair County County's temperate climate. St. Clair County County averages a 214-day frost-free season, with last frost around April 2 and first frost around November 2.

🌱

Your St. Clair County Garden Planner — Free

A 22-page printable planner built for St. Clair County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Clair County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.