🍠 Can I Plant Radish in Denver, CO?

2026 planting guide for Zone 5b · Last frost ~May 7 · Growing season ~153 days

✅ YES — Good temps, but watch for heat — highs near 97°F

Temperature conditions are suitable for Radish. Highs near 97°F are on the warm side — make sure plants have plenty of water. The season is running warmer than normal, which has opened this window earlier than usual.

Planting window: Apr 29 – May 13
Good to go — plant now while conditions are right.
Live result based on current forecast for Denver, CO · Updates every 6 hours
USDA Zone
5b
Last Spring Frost
~May 7
First Fall Frost
October 7
Growing Season
~153 days
Ideal Temp for Radish
40–65°F
Frost Risk
✅ Tolerant

Growing Radish in Denver

Denver's Zone 5b location at 5,280 feet elevation means gardeners face late spring frosts (sometimes into May) and early fall frosts (as early as late September). The intense high-altitude sun and dry air accelerate both plant growth and water loss. Row covers, raised beds, and careful timing are key to Denver gardening success.

In Denver (last frost around May 7), radish can go out around March — approximately 6 weeks before the last expected frost, making it an early-season opportunity.

Radish thrives between 40°F and 65°F. It tolerates temperatures as low as 32°F, making it a candidate for early spring planting before the last frost date. Expect 22–30 days from transplant to first harvest. One of the fastest vegetables. Spring or fall.

Frequently Asked Questions

When can I plant radish in Denver, CO?

In Denver (last frost around May 7), radish can go out around March — approximately 6 weeks before the last expected frost, making it an early-season opportunity.

What is the USDA hardiness zone for Denver?

Denver, CO is in USDA Plant Hardiness Zone 5b. The last expected spring frost is around May 7, and the first fall frost arrives around October 7. This zone classification helps you understand which perennials survive winter and when annual vegetables can safely go outdoors.

Is it safe to plant radish outside in Denver right now?

That depends on the current weather forecast. Radish needs temperatures above 32°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 radish in Denver 2026?

Yes — Radish grows well in Denver, CO. With a Zone 5b climate and a growing season of ~153 days, Denver is well-suited for cool-season crops like radish. As a frost-tolerant crop, radish can even go out a few weeks before the last frost date.

Grow Radish in Other Cities

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

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