Grand Junction, Colorado planting calendar and frost dates
Grand Junction is in USDA hardiness zone 6b. The last spring frost typically comes around April 28 and the first fall frost around October 16, giving about 171 frost-free days a year.
- Typical last frost
- April 28
- Typical first frost
- October 16
- Frost-free season
- 171 days
Frost dates in Grand Junction
Last spring frost
- April 11Risky: frost later than this in 9 years out of 10
- April 28Typical: a later frost in half of years
- May 14Safe: a later frost only 1 year in 10
First fall frost
- October 3Risky: frost earlier than this 1 year in 10
- October 16Typical: an earlier frost in half of years
- October 29Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 171 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 13 and returns around October 27.
NOAA U.S. Climate Normals 1991-2020 for Grand Junction Walker Fld, 6.1 miles SSE of the city center and 112 feet lower. 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 Grand Junction
January
Start indoors: onions
February
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, peppers, petunias, ranunculus, rosemary, snapdragons
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: beets, black-eyed susans, blackberries, blueberries, broccoli, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, ranunculus, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, perennial ryegrass, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, turnips
May
Start indoors: zinnias
Plant or sow outdoors: asparagus, basil, cantaloupes, celery, chives, cilantro, cosmos, cucumbers, dahlias, dill, eggplants, garden mums, ginger, gladioli, grapes, green beans, green onions, kentucky bluegrass, lavenders, lettuce, lilies, marigolds, mints, nasturtiums, okra, oregano, parsley, peanuts, peppers, perennial ryegrass, petunias, pumpkins, ranunculus, rosemary, sage, spinach, sunflowers, sweet corn, sweet peas, sweet potatoes, swiss chard, tall fescue, thyme, tomatoes, watermelons, winter squash, zucchini
June
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, zinnias, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, st. augustinegrass, zoysiagrass
Plant for fall: bearded irises, broccoli, brussels sprouts, carrots, collard greens, lettuce, peas, snapdragons, swiss chard
August
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, spinach, tall fescue, tulips
October
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in Grand Junction
Grand Junction's 6 main ZIP codes take their frost dates from 3 different NOAA stations: the typical last frost ranges from April 23 in 81503 to April 28 in 81506. The hardiness zone is 6b in 81505, and 7a in 81501, 81503, 81504, 81506, 81507.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 81501 | 7a | Grand Junction Walker Fld, 4.3 mi N | Apr 28 | Oct 16 |
| 81503 | 7a | Grand Junction 6ese, 1.2 mi ENE | Apr 23 | Oct 20 |
| 81504 | 7a | Grand Junction Walker Fld, 2.9 mi WNW | Apr 28 | Oct 16 |
| 81505 | 6b | Grand Junction Walker Fld, 6.1 mi SSE | Apr 28 | Oct 16 |
| 81506 | 7a | Grand Junction Walker Fld, 1.2 mi ENE | Apr 28 | Oct 16 |
| 81507 | 7a | Colorado Nm, 7.7 mi NW | Apr 26 | Oct 16 |
Planting dates for popular crops in Grand Junction
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 16 to 30 | May 11 to 25 | — |
| Strawberries | — | Mar 17 to 31 | — |
| Lettuce | Mar 3 to 17 | Apr 21 to May 5 | Jul 17 to Aug 21 |
| Cilantro | Mar 17 to 31 | Apr 28 to May 5 | — |
| Basil | Mar 23 to Apr 6 | May 11 to 18 | — |
| Potatoes | — | Apr 8 to 15 | — |
| Garlic | — | Mar 17 to 31 | Oct 16 to 30 |
| Onions | Jan 6 to Feb 17 | Mar 31 to Apr 14 | — |
| Cucumbers | Apr 13 to 27 | May 11 to 25 | — |
| Pumpkins | Apr 14 to 28 | May 12 to 26 | — |
| Peppers | Feb 23 to Mar 23 | May 11 to 25 | — |
| Carrots | — | Apr 7 to 28 | Jul 24 to Aug 14 |
| Sweet Potatoes | — | May 24 to 31 | — |
| Watermelons | Apr 6 to 20 | May 11 to 25 | — |
| Sweet Corn | — | Apr 28 to May 12 | — |
| Green Beans | — | May 11 to 25 | — |
| Zucchini | Apr 13 to 27 | May 11 to 25 | — |
| Broccoli | Feb 10 to Mar 3 | Mar 31 to Apr 14 | Jul 31 to Aug 28 |
| Peas | — | Mar 17 to 31 | Jul 24 to Aug 7 |
| Spinach | Mar 17 to 24 | Apr 21 to May 5 | Aug 7 to Sep 11 |
| Sunflowers | — | Apr 28 to May 19 | — |
| Zinnias | May 10 to 17 | Jun 7 to 21 | — |
| Tulips | — | — | Sep 4 to Oct 30 |
| Daffodils | — | — | Sep 4 to Oct 16 |
| Grass Seed | — | Mar 17 to 31 | Sep 4 to 18 |
Nearby cities
- Provo, UT zone 6b, last frost Apr 18
- Orem, UT zone 7a, last frost Apr 17
- Boulder, CO zone 6a, last frost May 6
- Lakewood, CO zone 6a, last frost May 5
- Arvada, CO zone 6a, last frost May 5
- Westminster, CO zone 6a, last frost May 2
Planting in ColoradoAbout zone 6bPrintable calendar for Grand Junction
Questions
When is the last frost in Grand Junction?
Around April 28 in a typical year, based on NOAA's 1991-2020 records for Grand Junction Walker Fld. There is still a 1 in 10 chance of frost after May 14.
What planting zone is Grand Junction in?
USDA hardiness zone 6b (2023 map), with parts of the city in zone 7a. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Grand Junction?
Start seeds indoors March 16 to 30 and set plants out May 11 to 25; the safest date to plant out is after May 14.
When is the first frost in Grand Junction?
Around October 16 in a typical year, and before October 3 about 1 year in 10.