When to Plant in Greeley, CO

Greeley, Colorado, experiences a median last spring frost on May 4 and a median first fall frost on October 1, resulting in approximately 150 frost-free days for planting. Gardeners in this region can take advantage of this growing season to cultivate a variety of crops and flowers; however, careful planning around these frost dates is essential to ensure successful harvests.

The unique microclimate of Greeley can be classified as continental mountain (cold nights, intense sun), which creates distinct challenges and advantages for gardening. Crops such as tomatoes, peppers, and sunflowers thrive in the intense sunlight, benefiting from the warm days, while crops like lettuce and other leafy greens may struggle with the hot afternoons and prefer cooler surroundings. Cold nights can potentially damage sensitive plants if not monitored carefully.

What to plant now in Greeley

Spring: Start planting cool-season crops like peas and spinach outdoors after the last frost date of May 4. This window is ideal for transitioning into warm-weather crops as temperatures rise.
Summer: Begin to plant heat-loving crops such as tomatoes and peppers in late May after the final frost. Ensure consistent watering to cope with summer heat and sun exposure.
Fall: Plant fast-maturing crops such as radishes and turnips in early September. Be mindful of the first frost date of October 1 to harvest before cold damages your crops.
Winter: In winter, concentrate on indoor gardening or preparing the garden for spring. Consider starting seedlings indoors, so they're ready for planting by late April.

In Greeley (150 frost-free days, a moderate season), 34 of 56 planner crops fit outright, 21 get two plantings, 1 crop is perennial.

Month by month in Greeley

Month	What to do
January	In January, plan your garden layout and order seeds. Consider your frost dates and think about which crops you want to plant in the coming seasons.
February	As February arrives, begin starting seeds indoors for early plants like tomatoes and peppers. This will give them a head start for planting after the last frost on May 4.
March	March is the time to prepare your outdoor garden beds and continue starting seeds indoors. Watch the temperatures closely, as spring is near but frost may still occur.
April	In April, your focus should be on hardening off seedlings started indoors. You can also plant cold-tolerant crops outdoors as the last frost date approaches.
May	May ushers in the last spring frost on May 4. After this date, you can safely plant warm-season crops like corn and beans in your garden.
June	June involves maintaining your garden and ensuring proper watering as plants grow rapidly. This month is crucial for monitoring pests and diseases.
July	In July, continue caring for your crops and start planning for fall planting. Be prepared for hot days that might stress your plants if not properly watered.
August	August represents the peak of summer gardening. Ensure you harvest vegetables like zucchini and squash regularly, and begin seeding fall crops by the end of the month.
September	September is when you can plant fast-maturing fall crops such as radishes and turnips. Be mindful of the impending first frost on October 1.
October	With the first fall frost date on October 1, ensure you harvest all crops. Cleanup and preparation for winter gardening chores should be your focus now.
November	In November, prepare your garden for winter. Consider mulching to protect perennials and maintaining tools for the next gardening season.
December	December is ideal for indoor gardening. Plan next year's garden and reflect on what worked well, ensuring you are ready for the spring planting season.

Frost dates for Greeley ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
80634	May 4	October 1	5b
80631	May 4	October 1	5a

FAQ

When is the last frost in Greeley?

The last frost in Greeley typically occurs on May 4, signaling the time when gardeners can safely start planting warm-season crops.

What vegetables grow best in Greeley?

Vegetables such as tomatoes, peppers, and corn thrive in Greeley due to the abundant sunlight and warmer daytime temperatures. However, crops like spinach may struggle due to intense summer heat.

When should I plant tomatoes in Greeley?

Tomatoes should be planted outside after the last frost date of May 4 to ensure they thrive in warm weather and avoid frost damage.

Can I garden year-round in Greeley?

While the gardening season is limited due to the frost dates, indoor gardening can provide year-round opportunities, especially with herbs and other houseplants.

How does Plan My Garden help Greeley gardeners?

Plan My Garden provides tailored advice based on localized frost dates and planting zones, helping Greeley gardeners maximize their yield and effectively plan their seasons.