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What Grows in Denver, CO?

Denver's mile-high elevation and 300 sunny days create unique conditions — intense UV but late spring frosts.

Zone

USDA 6a

Last frost

May 5

First frost

September 28

Frost-free days

157
Quick Answer

Denver is in USDA Zone 6a with about 157 frost-free days, and you can grow tomatoes, peppers, beans, beets, and more here.

Planting tips for Denver

Last frost around May 7. Start seeds indoors in March. Use wall-o-waters for early tomatoes.

What to plant, and when

Timing by your frost dates — last frost May 5, first frost September 28.

🌱 Start indoors (pre-frost)

Tomato, Cherry Tomato, Bell Pepper, Chili Pepper, Cucumber, Zucchini, Eggplant, Pumpkin

❄️ Direct-sow early (cool season)

Lettuce, Spinach, Kale, Broccoli, Carrot, Radish, Beets, Onion

☀️ Plant after last frost

Green Beans, Potato, Sweet Potato, Corn, Microgreens, Rhubarb

🍂 Plant in fall

Garlic

What grows well in Denver

USDA Zone 6a

Frequently asked questions

What hardiness zone is Denver, CO in?

Denver, CO is in USDA Hardiness Zone 6a. This drives everything about what you can reliably grow — it maps directly to how cold your winters get.

When is the last frost in Denver?

The average last spring frost in Denver is around May 5, and the first fall frost is typically September 28. Plan to move tender plants outside after May 5 and have them harvested (or protected) before September 28.

What grows well in Denver?

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

How long is Denver's growing season?

Denver typically has around 157 frost-free days per year (roughly May 5 to September 28). That's a full season — plenty of time for most annual vegetables plus a succession or fall crop of cool-season greens.

What should I plant first in Denver?

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 Denver.

Can I grow vegetables in containers in Denver?

Yes — Denver'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.

When should I start seeds indoors in Denver?

For warm-season crops like Tomato, Cherry Tomato, Bell Pepper, start seeds indoors 6–8 weeks before your last frost (around May 5), then transplant after the danger of frost has passed.