🌸 Can I Plant Rhubarb in St. Louis, MO?

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

✅ YES — Good temps, but watch for heat — highs near 90°F

Temperature conditions are suitable for Rhubarb. Highs near 90°F are on the warm side — make sure plants have plenty of water.

Planting window: Jul 16 – Jul 30
Good to plant now — rhubarb is a perennial, so expect first harvest in 2027.
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 Rhubarb
40–75°F
Frost Risk
✅ Tolerant

Growing Rhubarb 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), rhubarb can go out around March — approximately 2 weeks before the last expected frost, making it an early-season opportunity.

Rhubarb thrives between 40°F and 75°F. It tolerates temperatures as low as 20°F, making it a candidate for early spring planting before the last frost date. Expect 365–730 days from transplant to first harvest. Do not harvest in the first year. Leaves are toxic — eat stalks only. Thrives with cold winters.

Frequently Asked Questions

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

In St. Louis (last frost around April 5), rhubarb can go out around March — approximately 2 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 rhubarb outside in St. Louis right now?

That depends on the current weather forecast. Rhubarb needs temperatures above 20°F (ideally 40–75°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 rhubarb in St. Louis 2026?

Yes — Rhubarb 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 rhubarb. As a frost-tolerant crop, rhubarb can even go out a few weeks before the last frost date.

Grow Rhubarb in Other Cities

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

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