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When to plant Basil in Benton County, MN

For Basil in Benton County, the safe spring window opens around May 9 and closes around May 30. Last expected frost is May 2, first fall frost October 6, giving a 157-day growing season.

When to Plant Basil in Benton County, MN

Basil
Benton County, Minnesota Zone 4a June

Top priorities for Benton County, Minnesota gardeners in June

Your Benton County, Minnesota garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 2
Avg. first frost October 6
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.5 hrs
  1. Indoor seed-starting week for basil

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Looking ahead to July
  • First harvests: basil

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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.

Benton County, Minnesota is in USDA Zone 4a. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.

At an elevation of 1,178 feet, Benton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Basil to ensure they mature before fall.

Benton County, MN (Zone 4a) Moderate season
157 days
Last Spring Frost May 2
157 growing days
First Fall Frost October 6

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Mar 1 Transplant: May 17 🍅 Harvest: Jul 12 – Sep 13
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 7 Transplant: May 23 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Mar 24 Transplant: Jun 9 🍅 Harvest: Aug 4 – Oct 6

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 Benton County

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

Soil pH

Your soil pH (6.0–7.0) is within Basil's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Benton County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Basil.

Organic Matter

Organic matter is excellent (4.9%) — Basil will thrive.

How to Plant Basil

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

Succession Planting Basil

3
successive plantings in your 157-day season

Sow every 5.7 weeks. Last sowing by Jul 23 to harvest before frost.

Basil Water Budget

Plant needs
0.6″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 2.6" 4.1" 0" ✅ Rainfall sufficient
Jun 2.6" 5" 0" ✅ Rainfall sufficient
Jul 2.6" 4.5" 0" ✅ Rainfall sufficient
Aug 2.6" 4.2" 0" ✅ Rainfall sufficient
Sep 2.6" 3.3" 0" ✅ Rainfall sufficient
Oct 2.6" 3.3" 0" ✅ Rainfall sufficient
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Benton County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~812 GDD — county provides 2,041 GDD Excellent fit

Basil Planting Timeline — Benton County, MN

Basil Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 9 May 9 – May 30
Harvest July 18 Jul 18 – Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

157 days in Benton County

Growing Tips for Basil in Benton County

Direct sow Basil outdoors after May 02 in Benton 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 →

🌾 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 Benton County, MN?

Benton County is in Zone 4a with an average last frost of May 2. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, MN?

Benton County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 2 and first fall frost is October 6.

When should I plant Basil in Benton County, MN?

In Benton County, MN, plant Basil after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Benton County, MN for Basil?

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

Can Basil grow in Benton County's climate?

Yes — Basil grows well in Benton County's temperate climate. Benton County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.

🌱

Your Benton County Garden Planner — Free

A 22-page printable planner built for Benton County (Zone 4a). 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 Benton County, MN. 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.