🥬 Can I Plant Mustard Greens in St. Louis, MO?
Temperature conditions are suitable for Mustard Greens. Highs near 90°F are on the warm side — make sure plants have plenty of water.
Growing Mustard Greens 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), mustard greens can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity.
Mustard Greens thrives between 40°F and 65°F. It tolerates temperatures as low as 25°F, making it a candidate for early spring planting before the last frost date. Expect 25–45 days from transplant to first harvest. Fast-growing cool-season green. Bolts in heat.
Frequently Asked Questions
When can I plant mustard greens in St. Louis, MO?
In St. Louis (last frost around April 5), mustard greens can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity.
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 mustard greens outside in St. Louis right now?
That depends on the current weather forecast. Mustard Greens needs temperatures above 25°F (ideally 40–65°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 mustard greens in St. Louis 2026?
Yes — Mustard Greens 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 mustard greens. As a frost-tolerant crop, mustard greens can even go out a few weeks before the last frost date.
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