🌿 Can I Plant Mint in St. Louis, MO?

2026 planting guide for Zone 6b · Last frost ~April 5 · Growing season ~203 days

✅ YES — Conditions look good

Temperature conditions are suitable for Mint.

Planting window: Jul 16 – Jul 30
Good to go — plant now while conditions are right.
Live result based on current forecast for St. Louis, MO · Updates every 6 hours
USDA Zone
6b
Last Spring Frost
~April 5
First Fall Frost
October 25
Growing Season
~203 days
Ideal Temp for Mint
55–85°F
Frost Risk
✅ Tolerant

Growing Mint in St. Louis

St. Louis sits at the confluence of the Missouri and Mississippi rivers in Zone 6b, with about 202 frost-free days. The humid continental climate brings warm, productive summers ideal for tomatoes, peppers, cucumbers, and sweet corn. Spring arrives relatively early, and fall holds warmth well — excellent conditions for a September planting of cool-season greens that produce into November.

In St. Louis (last frost around April 5), mint can go out around March — approximately 2 weeks before the last expected frost, making it an early-season opportunity. Starting seeds indoors 8 weeks before the last frost date gives you a significant head start.

Mint thrives between 55°F and 85°F. It tolerates temperatures as low as 28°F, making it a candidate for early spring planting before the last frost date. Expect 30–60 days from transplant to first harvest. Very vigorous. Grow in containers to control spread.

Frequently Asked Questions

When can I plant mint in St. Louis, MO?

In St. Louis (last frost around April 5), mint can go out around March — approximately 2 weeks before the last expected frost, making it an early-season opportunity. For best results, start seeds indoors 8 weeks before that — giving you strong transplants ready to go out at the right time.

What is the USDA hardiness zone for St. Louis?

St. Louis, MO is in USDA Plant Hardiness Zone 6b. The last expected spring frost is around April 5, and the first fall frost arrives around October 25. This zone classification helps you understand which perennials survive winter and when annual vegetables can safely go outdoors.

Is it safe to plant mint outside in St. Louis right now?

That depends on the current weather forecast. Mint needs temperatures above 28°F (ideally 55–85°F) to thrive. CanIPlant checks your real 7-day forecast and any active frost alerts to give you a live YES, NO, or WAIT answer — just enter your ZIP code.

Can I grow mint in St. Louis 2026?

Yes — Mint grows well in St. Louis, MO. With a Zone 6b climate and a growing season of ~203 days, St. Louis is well-suited for cool-season crops like mint. As a frost-tolerant crop, mint can even go out a few weeks before the last frost date.

Grow Mint in Other Cities

New York, NYLos Angeles, CAChicago, ILHouston, TXPhoenix, AZPhiladelphia, PASan Antonio, TXSan Diego, CA

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