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When to plant Basil in Lake County, IL

Plant Basil in Lake County, when soil hits 50°F — usually April 28. Continue planting through May 19 for the spring crop.

When to Plant Basil in Lake County, IL

Basil

Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Lake County, Illinois is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 20, giving you a growing season of approximately 182 days.

At an elevation of 1,080 feet, Lake County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Basil to ensure they mature before fall.

Lake County, IL (Zone 6a) Moderate season
182 days
Last Spring Frost April 21
182 growing days
First Fall Frost October 20

Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.9

Drainage

Well Drained

Monthly Watering Guide for Basil

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

Month Basil Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Basil Planting Timeline — Lake County, IL

Basil Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 28 Apr 28 – May 19
Harvest June 30 Jun 30 – Sep 1

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

182 days in Lake County

Growing Tips for Lake County

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Lake County, IL?

Lake County is in Zone 6a with an average last frost of April 21. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, IL?

Lake County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 20.

When should I plant Basil in Lake County, IL?

In Lake County, IL, plant Basil after the last frost (around April 21) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Lake County, IL for Basil?

Lake County sits in USDA Zone 6a. Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Basil grow in Lake County's climate?

Yes — Basil grows well in Lake County's temperate climate. Lake County averages a 182-day frost-free season, with last frost around April 21 and first frost around October 20.

🌱

Your Lake County Garden Planner — Free

A 22-page printable planner built for Lake 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.

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 Lake County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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