What Grows in O Fallon, MO?

O Fallon, MO is in USDA Hardiness Zone 6b. This drives everything about what you can reliably grow — it maps directly to how cold your winters get.

The average last spring frost in O Fallon is around mid-March, and the first fall frost is typically mid-November. Plan to move tender plants outside after mid-March and have them harvested (or protected) before mid-November.

Plenty — O Fallon's USDA Zone 6b climate supports 30+ crops. Some of the easiest and most reliable here are Cherry Tomato, Chili Pepper, Cucumber.

O Fallon typically has around 244 frost-free days per year (roughly mid-March to mid-November). That's a full season — plenty of time for most annual vegetables plus a succession or fall crop of cool-season greens.

Go with fast-maturing crops to get a quick win while the season is short: Microgreens, Arugula, Radish are among the quickest from seed to harvest in O Fallon.

Yes — O Fallon's climate is container-friendly for the right crops. Tomato, Cherry Tomato, Bell Pepper all do well in pots, which also lets you start them a little earlier and move them in on cold nights.

For warm-season crops like Tomato, Cherry Tomato, Bell Pepper, start seeds indoors 6–8 weeks before your last frost (around mid-March), then transplant after the danger of frost has passed.