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When to Plant Basil in New Hampshire

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.

New Hampshire spans USDA hardiness zones 4a, 4b, 5a, 5b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Basil planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Basil Planting Calendar for New Hampshire

Zone 4a ~145 day growing season · Full guide →

Last frost: May 6 · First frost: September 28 · 145 day season

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 13 May 13 – Jun 3
Harvest July 22 Jul 22 – Sep 23
Zone 4b ~155 day growing season · Full guide →

Last frost: May 1 · First frost: October 3 · 155 day season

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
Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 2 May 2 – May 23
Harvest July 4 Jul 4 – Sep 5
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

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

Growing Tips for New Hampshire

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.

Frequently Asked Questions

When should I plant Basil in New Hampshire?

Planting dates for Basil in New Hampshire depend on your USDA zone. New Hampshire spans zones 4a, 4b, 5a, 5b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is New Hampshire for planting?

New Hampshire contains USDA hardiness zones 4a, 4b, 5a, 5b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.