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When to Plant Basil in Brown County, OH

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.

Brown County, Ohio is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 1,146 feet, Brown County receives approximately 32 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Basil during the growing season.

Brown County, OH (Zone 6a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Brown County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🍅 Harvest: Jun 19 – Aug 21
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: Mar 20 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 18

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Brown County

How your county's soil matches Basil's growing requirements.

Soil pH

Your soil pH (6.0โ€“6.9) is within Basil's preferred range (6.0โ€“7.0).

Soil Texture

The silt loam soil in Brown County is excellent for Basil โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Basil.

Organic Matter

Organic matter is excellent (4.8%) โ€” Basil will thrive.

How to Plant Basil

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Basil

4
successive plantings in your 189-day season

Sow every 5.7 weeks. Last sowing by Aug 10 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 139 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2" 0" โ„๏ธ Dormant
Apr 2.6" 2.9" 0" โœ… Rainfall sufficient
May 2.6" 4.1" 0" โœ… Rainfall sufficient
Jun 2.6" 4.1" 0" โœ… Rainfall sufficient
Jul 2.6" 3.5" 0" โœ… Rainfall sufficient
Aug 2.6" 3.2" 0" โœ… Rainfall sufficient
Sep 2.6" 2.7" 0" โœ… Rainfall sufficient
Oct 2.6" 2.3" 0.3" ๐Ÿ’ง Light watering
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Brown County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Basil Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Basil needs ~1,000 GDD — county provides 3,024 GDD Excellent fit

Basil Planting Timeline โ€” Brown County, OH

Basil Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 โ€“ Mar 14
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest June 27 Jun 27 โ€“ Aug 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

189 days in Brown County

Growing Tips for Basil in Brown County

Direct sow Basil outdoors after April 18 in Brown County when soil has warmed and frost danger has passed.

General growing tips

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 →

๐ŸŒพ 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 35ยฐF, under 45% humidity.

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

Frequently Asked Questions

When should I plant Basil in Brown County, OH?

Brown County is in Zone 6a with an average last frost of April 18. Plan your Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Brown County, OH?

Brown County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Brown County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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