Parker, Colorado planting calendar and frost dates
Parker is in USDA hardiness zone 5b. The last spring frost typically comes around May 9 and the first fall frost around October 3, giving about 145 frost-free days a year.
- Typical last frost
- May 9
- Typical first frost
- October 3
- Frost-free season
- 145 days
Frost dates in Parker
Last spring frost
- April 27Risky: frost later than this in 9 years out of 10
- May 9Typical: a later frost in half of years
- May 23Safe: a later frost only 1 year in 10
First fall frost
- September 21Risky: frost earlier than this 1 year in 10
- October 3Typical: an earlier frost in half of years
- October 15Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 145 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 29 and returns around October 12.
NOAA U.S. Climate Normals 1991-2020 for Parker, 2.7 miles NE 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 Parker
January
Start indoors: onions
February
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons
March
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, kale, leeks, lettuce, marigolds, nasturtiums, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard
Plant or sow outdoors: black-eyed susans, blueberries, garlic, grapes, grass seed, hollyhocks, onions, peas, poppies, raspberries, rhubarb, strawberries, turnips, wildflowers
April
Start indoors: basil, cantaloupes, celery, cilantro, cosmos, cucumbers, eggplants, marigolds, nasturtiums, okra, peppers, pumpkins, ranunculus, spinach, swiss chard, 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
May
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, basil, beets, cantaloupes, carrots, cauliflower, chives, cilantro, cucumbers, dahlias, dill, eggplants, figs, garden mums, ginger, gladioli, grapes, green beans, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, peppers, perennial ryegrass, petunias, potatoes, pumpkins, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, tomatoes, watermelons, winter squash, zucchini
June
Start indoors: zinnias
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, green beans, green onions, okra, peanuts, peppers, pumpkins, st. augustinegrass, sweet potatoes, tomatoes, watermelons, winter squash, zinnias, zoysiagrass, zucchini
Plant for fall: brussels sprouts
July
Plant or sow outdoors: bermudagrass, centipedegrass, green onions, okra, 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
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
September
Plant for fall: crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, lilies, ornamental alliums, peonies, radishes, saffron, tulips
October
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in Parker
Parker's 2 main ZIP codes take their frost dates from 2 different NOAA stations: the typical last frost ranges from May 4 in 80138 to May 9 in 80134. Every one of them is in zone 5b.
Planting dates for popular crops in Parker
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Apr 1 to 15 | May 27 to Jun 10 | — |
| Strawberries | — | Mar 28 to Apr 11 | — |
| Lettuce | Mar 14 to 28 | May 2 to 16 | Jul 4 to Aug 8 |
| Cilantro | Mar 28 to Apr 11 | May 9 to 16 | — |
| Basil | Apr 8 to 22 | May 27 to Jun 3 | — |
| Potatoes | — | Apr 27 to May 4 | — |
| Garlic | — | Mar 28 to Apr 11 | Oct 3 to 17 |
| Onions | Jan 17 to Feb 28 | Apr 11 to 25 | — |
| Cucumbers | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Pumpkins | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Peppers | Mar 11 to Apr 8 | May 27 to Jun 10 | — |
| Carrots | — | Apr 18 to May 9 | Jul 11 to Aug 1 |
| Sweet Potatoes | — | Jun 10 to 17 | — |
| Watermelons | Apr 22 to May 6 | May 27 to Jun 10 | — |
| Sweet Corn | — | May 9 to 23 | — |
| Green Beans | — | May 27 to Jun 10 | — |
| Zucchini | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Broccoli | Feb 21 to Mar 14 | Apr 11 to 25 | Jul 18 to Aug 15 |
| Peas | — | Mar 28 to Apr 11 | Jul 11 to 25 |
| Spinach | Mar 28 to Apr 4 | May 2 to 16 | Jul 25 to Aug 29 |
| Sunflowers | — | May 9 to 30 | — |
| Zinnias | Jun 1 to 8 | Jun 29 to Jul 13 | — |
| Tulips | — | — | Aug 22 to Oct 17 |
| Daffodils | — | — | Aug 22 to Oct 3 |
| Grass Seed | — | Mar 28 to Apr 11 | Aug 22 to Sep 5 |
Nearby cities
- Centennial, CO zone 6a, last frost May 5
- Castle Rock, CO zone 5b, last frost May 16
- Aurora, CO zone 6a, last frost May 4
- Denver, CO zone 6a, last frost May 4
- Lakewood, CO zone 6a, last frost May 5
- Commerce City, CO zone 6a, last frost May 4
Planting in ColoradoAbout zone 5bPrintable calendar for Parker
Questions
When is the last frost in Parker?
Around May 9 in a typical year, based on NOAA's 1991-2020 records for Parker. There is still a 1 in 10 chance of frost after May 23.
What planting zone is Parker in?
USDA hardiness zone 5b (2023 map), with parts of the city in zone 6a. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Parker?
Start seeds indoors April 1 to 15 and set plants out May 27 to June 10.
When is the first frost in Parker?
Around October 3 in a typical year, and before September 21 about 1 year in 10.