Planting Guides

When to Plant Basil in Minneapolis: Complete Guide + Best Varieties for Zone 4a

Minneapolis, Minnesota

USDA Zone 4a

Last Frost: May 15

Last updated: October 30, 2025

Plant basil in Minneapolis after May 15 when soil reaches 60°F. Start seeds indoors April 1-15 for transplant success in Zone 4a's short season.

AAmanda Foster

October 30, 2025

When to plant basil in Minneapolis - healthy basil varieties in containers on urban balcony — — Image © PlantReference.org 2026

Quick Answer

Start basil seeds indoors April 1-15 in Minneapolis. Transplant outdoors after May 15 when soil reaches 60°F consistently.

TL;DR

Plant basil in Minneapolis after May 15 when soil temperatures reach 60°F consistently. Start seeds indoors April 1-15 for transplant success. Ocimum basilicum 'Genovese' and Ocimum basilicum 'Thai' are most reliable varieties for Zone 4a's 138-day growing season. Harvest before September 30 first frost.

Frequently Asked Questions

When exactly should I plant basil outdoors in Minneapolis?

Wait until soil temperatures reach 60°F consistently at 4-inch depth, typically May 15-25 in Minneapolis. Check the 10-day forecast for overnight lows above 50°F before transplanting. Basil suffers permanent damage from cold soil, even if air temperatures seem warm enough.

Can I direct sow basil seeds in Minneapolis, or must I start indoors?

Indoor starting is strongly recommended for Minneapolis's Zone 4a climate. Direct sowing success rates drop to 60-70% compared to 90%+ for transplants. If attempting direct seeding, wait until June 1-10 when soil reaches 65°F+ consistently. Use row covers for protection and expect delayed harvest.

Which basil varieties work best for Minneapolis's short growing season?

Ocimum basilicum 'Genovese' and Ocimum basilicum 'Thai' are most reliable, maturing in 60-85 days. Ocimum basilicum 'Lemon' and Ocimum basilicum 'Spicy Globe' also succeed. Avoid Ocimum tenuiflorum (Holy Basil) and perennial varieties that need 90+ days to establish.

How can I extend the basil growing season in Minneapolis?

Start seeds indoors by April 1st for earliest possible transplants. Use containers that can move indoors during cold snaps. Install row covers or cold frames for spring and fall protection. Plan final harvest before September 30 when first frost typically occurs.

What should I do if my basil gets hit by an unexpected late frost in Minneapolis?

Assess damage immediately after frost. If less than 50% of leaves are blackened, the plant may recover. Remove damaged foliage and provide protection for remaining growth. If damage exceeds 50%, replace with new seedlings. Late frosts after May 15 occur approximately every 3-4 years in Minneapolis.

How do I prevent my basil from bolting in Minneapolis summer heat?

Pinch flower spikes weekly as soon as they appear. Provide afternoon shade during heat waves above 90°F. Maintain consistent soil moisture without waterlogging. Regular harvesting also prevents energy from going to flower production.

Can I grow basil year-round indoors in Minneapolis?

Yes, but success requires supplemental lighting and proper conditions. Use full-spectrum LED grow lights for 12-14 hours daily. Maintain 65-75°F temperatures and good air circulation. Choose compact varieties like Ocimum basilicum 'Spicy Globe' for indoor growing. Expect slower growth than outdoor plants.

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Tagged with

#basil planting #Minneapolis gardening #Zone 4a #when to plant basil #Minnesota vegetables #herb gardening #frost dates #seed starting #container gardening #short season growing

Written By

Amanda Foster

Amanda came to gardening through an unexpected route—after developing chronic pain from rheumatoid arthritis in her late 20s, she started researching adaptive gardening techniques that would allow her to continue growing plants without aggravating her condition. Now based in Minneapolis, she writes about accessible gardening, raised bed designs for people with mobility challenges, and ergonomic tools that reduce strain. Amanda completed a certificate in sustainable urban agriculture and volunteers with a nonprofit that builds accessible community gardens. She grows vegetables, herbs, and flowers in waist-high raised beds she designed herself. Her writing focuses on practical solutions that work for real people with real limitations—whether that's arthritis, limited mobility, or just a bad back.