When to plant basil in Minnesota
Minnesota’s average last spring frost is May 6, and the first fall frost typically arrives around September 28 — about 145 frost-free days (USDA zones 3a, 3b, 4a, 4b, 5a). Basil needs 30–60 days to mature, which fits comfortably within Minnesota's growing season.
When to plant basil in Minnesota: the short answer
For a spring planting, plant out May 13 – May 30, with seeds started indoors Mar 25 – Apr 8. Wait until the soil is at least 65°F and frost is over.
Succession sow again in Minnesota: Jun 10 · Jul 1 · Jul 22 · Aug 12
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow basil in Minnesota, step by step
- Start seeds indoors (Mar 25 – Apr 8). Sow seeds ⅛ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 80°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 10 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (May 13 – May 30). Space plants about 10 inches apart in rows 12 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: aphids, Japanese beetle, slugs. Diseases and disorders: basil downy mildew, fusarium wilt, damping off.
- Harvest (from about Jun 19 – Jul 19). Basil takes 30-60 days to reach harvest. Cold soil stalls it - wait for warm nights. Pinch above a leaf pair every couple of weeks and remove flower buds to keep leaves coming. Downy mildew-resistant varieties are worth seeking out.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full basil growing guide.
Basil planting dates by USDA zone in Minnesota
Minnesota spans USDA zones 3a, 3b, 4a, 4b, 5a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the basil dates shift with them.
When to plant basil in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant basil in Minnesota?
Plant basil transplants outdoors in Minnesota between May 13 and May 30. That timing is set by Minnesota's average last spring frost of May 6.
When should I start basil seeds indoors in Minnesota?
Start seeds indoors between March 25 and April 8, about 5 weeks before the last frost, so the seedlings are ready to plant out from May 13.
What is the latest I can plant basil in Minnesota?
About August 29. Basil needs at least 30 days to mature, and frost around September 28 ends the season, so later plantings risk being cut short.
When will basil planted in Minnesota be ready to harvest?
Planted on time, basil is usually ready from about June 19 to July 19, 30-60 days after planting.
When is the last frost in Minnesota?
On average around May 6, with the first fall frost around September 28 - about 145 frost-free days. Your town may differ by two weeks or more.