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When to plant Basil in Grant County, MN

Grant County gardeners should plant Basil between May 8 and May 29 in spring. With Grant County's Zone 4b climate (last frost May 1), Basil needs 50–75 days to mature — plant by July 24 for a full harvest.

When to Plant Basil in Grant County, MN

Basil
Grant County, Minnesota Zone 4b July

July to-do list for Grant County, Minnesota

A quick July briefing for Grant County, Minnesota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 15.2 hrs
  1. Bring in the basil

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of August
  • 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.

Grant County, Minnesota is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 1,371 feet, Grant County receives approximately 31.4 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.

Grant County, MN (Zone 4b) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Feb 28 Transplant: May 16 🍅 Harvest: Jul 11 – Sep 12
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Mar 6 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 18
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Mar 19 Transplant: Jun 4 🍅 Harvest: Jul 30 – Oct 1

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 Grant County

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

Soil pH

Your soil pH (6.1–6.8) is within Basil's preferred range (6.0–7.0).

Soil Texture

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

Drainage

Drainage is adequate for Basil.

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

3
successive plantings in your 159-day season

Sow every 5.7 weeks. Last sowing by Jul 24 to harvest before frost.

Basil Water Budget

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

Water stress score is 6/10 — 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 2.6" 4.1" 0" ✅ Rainfall sufficient
Jun 2.6" 4.4" 0" ✅ Rainfall sufficient
Jul 2.6" 3.7" 0" ✅ Rainfall sufficient
Aug 2.6" 2.9" 0" ✅ Rainfall sufficient
Sep 2.6" 3.2" 0" ✅ Rainfall sufficient
Oct 2.6" 2.1" 0.5" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Grant 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 ~766 GDD — county provides 1,947 GDD Excellent fit

Basil Planting Timeline — Grant County, MN

Basil Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 8 May 8 – May 29
Harvest July 17 Jul 17 – Sep 18

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 4b

📆 Growing Season

159 days in Grant County

Growing Tips for Basil in Grant County

Direct sow Basil outdoors after May 01 in Grant 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 Grant County, MN?

Grant County is in Zone 4b with an average last frost of May 1. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, MN?

Grant County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.

When should I plant Basil in Grant County, MN?

In Grant County, MN, plant Basil after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Grant County, MN for Basil?

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

Can Basil grow in Grant County's climate?

Yes — Basil grows well in Grant County's temperate climate. Grant County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 4b). 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 Grant County, MN. Local conditions may vary. Last updated: July 2026.

Sources & credits

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