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Greeley, Colorado planting calendar and frost dates

Greeley is in USDA hardiness zone 5b. The last spring frost typically comes around May 2 and the first fall frost around October 8, giving about 159 frost-free days a year.

Hardiness zone
Zone 5b (parts in 5a)
Typical last frost
May 2
Typical first frost
October 8
Frost-free season
159 days

Frost dates in Greeley

Last spring frost

  • April 17Risky: frost later than this in 9 years out of 10
  • May 2Typical: a later frost in half of years
  • May 14Safe: a later frost only 1 year in 10

First fall frost

  • September 26Risky: frost earlier than this 1 year in 10
  • October 8Typical: an earlier frost in half of years
  • October 21Late: frost before this in 9 years out of 10

The growing season between the typical last and first frosts is about 159 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around April 20 and returns around October 18.

NOAA U.S. Climate Normals 1991-2020 for Greeley Unc, 1.6 miles SSE of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.

What to plant each month in Greeley

  1. January

    Start indoors: onions

  2. February

    Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons

  3. March

    Start indoors: basil, black-eyed susans, broccoli, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, leeks, lettuce, marigolds, nasturtiums, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard, tomatoes

    Plant or sow outdoors: black-eyed susans, blueberries, garlic, grapes, grass seed, hollyhocks, kale, onions, peas, poppies, raspberries, rhubarb, strawberries, turnips, wildflowers

  4. April

    Start indoors: basil, cantaloupes, cilantro, cosmos, cucumbers, marigolds, nasturtiums, okra, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini

    Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garlic, gladioli, grapes, grass seed, green onions, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, potatoes, radishes, ranunculus, raspberries, rhubarb, roses, snapdragons, spinach, strawberries, swiss chard, turnips, wildflowers

  5. May

    Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zinnias, zucchini

    Plant or sow outdoors: asparagus, basil, beets, cantaloupes, carrots, celery, chives, cilantro, cosmos, cucumbers, dahlias, dill, eggplants, figs, garden mums, ginger, gladioli, grapes, green beans, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, okra, oregano, parsley, peanuts, peppers, perennial ryegrass, petunias, pumpkins, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, sweet potatoes, swiss chard, tall fescue, thyme, tomatoes, watermelons, winter squash, zucchini

  6. June

    Plant or sow outdoors: bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, green beans, green onions, okra, peanuts, peppers, pumpkins, st. augustinegrass, sweet potatoes, tomatoes, watermelons, winter squash, zinnias, zoysiagrass, zucchini

  7. July

    Plant or sow outdoors: bermudagrass, centipedegrass, st. augustinegrass, zinnias, zoysiagrass

    Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, lettuce, peas, radishes, snapdragons, spinach, swiss chard, turnips

  8. August

    Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hydrangeas, kale, lettuce, lilies, ornamental alliums, peonies, radishes, roses, saffron, snapdragons, spinach, swiss chard, tulips, turnips

  9. September

    Plant for fall: cabbages, cauliflower, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, lilies, ornamental alliums, peonies, radishes, saffron, spinach, tulips

  10. October

    Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips

Frost dates and zones by ZIP code in Greeley

All 4 of Greeley's main ZIP codes take their frost dates from Greeley Unc, so the dates on this page apply across the city. The hardiness zone is 5a in 80631, and 5b in 80543, 80550, 80634.

ZIP codeZoneWeather stationTypical last frostTypical first frost
805435bGreeley Unc, 1.6 mi SSEMay 2Oct 8
805505bGreeley Unc, 1.6 mi SSEMay 2Oct 8
806315aGreeley Unc, 1.6 mi SSEMay 2Oct 8
806345bGreeley Unc, 1.6 mi SSEMay 2Oct 8

Planting dates for popular crops in Greeley

PlantStart indoorsPlant or sow outdoorsFall planting
TomatoesMar 23 to Apr 6May 18 to Jun 1—
Strawberries—Mar 21 to Apr 4—
LettuceMar 7 to 21Apr 25 to May 9Jul 9 to Aug 13
CilantroMar 21 to Apr 4May 2 to 9—
BasilMar 30 to Apr 13May 18 to 25—
Potatoes—Apr 13 to 20—
Garlic—Mar 21 to Apr 4Oct 8 to 22
OnionsJan 10 to Feb 21Apr 4 to 18—
CucumbersApr 20 to May 4May 18 to Jun 1—
PumpkinsApr 20 to May 4May 18 to Jun 1—
PeppersMar 2 to 30May 18 to Jun 1—
Carrots—Apr 11 to May 2Jul 16 to Aug 6
Sweet Potatoes—May 31 to Jun 7—
WatermelonsApr 13 to 27May 18 to Jun 1—
Sweet Corn—May 2 to 16—
Green Beans—May 18 to Jun 1—
ZucchiniApr 20 to May 4May 18 to Jun 1—
BroccoliFeb 14 to Mar 7Apr 4 to 18Jul 23 to Aug 20
Peas—Mar 21 to Apr 4Jul 16 to 30
SpinachMar 21 to 28Apr 25 to May 9Jul 30 to Sep 3
Sunflowers—May 2 to 23—
ZinniasMay 20 to 27Jun 17 to Jul 1—
Tulips——Aug 27 to Oct 22
Daffodils——Aug 27 to Oct 8
Grass Seed—Mar 21 to Apr 4Aug 27 to Sep 10

Nearby cities

Planting in ColoradoAbout zone 5bPrintable calendar for Greeley

Questions

When is the last frost in Greeley?

Around May 2 in a typical year, based on NOAA's 1991-2020 records for Greeley Unc. There is still a 1 in 10 chance of frost after May 14.

What planting zone is Greeley in?

USDA hardiness zone 5b (2023 map), with parts of the city in zone 5a. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.

When should I plant tomatoes in Greeley?

Start seeds indoors March 23 to April 6 and set plants out May 18 to June 1.

When is the first frost in Greeley?

Around October 8 in a typical year, and before September 26 about 1 year in 10.