Parker, CO Vegetable Planting Calendar

What to plant now in Parker

In October:

• Plant garlic cloves (Oct 1–14)

The list above is for the month this page was built; the box is refreshed in your browser for today's date.

Spring planting dates

“Plant out” means transplanting for crops started indoors and sowing or planting directly in the garden for the others. Each column applies CSU Extension's timing rule to a different last-frost anchor: aggressive = typical date (May 9, 50% risk), balanced = May 14 (30%), safe = May 23 (10%). For hardy crops the cell shows the CSU “as early as” window.

Frost odds aren't the only check. CSU recommends measuring soil temperature at 4 inches (6 inches for beans) before you sow. NOAA doesn't publish soil-temperature normals, so we list each crop's minimum soil temperature from CSU instead of a date.

Fall planting dates

Latest dates for a fall harvest, using the University of Nebraska–Lincoln Extension count-back formula: days to harvest (CSU) + 14-day fall factor + 14-day frost-tender factor for frost-sensitive crops, counted back from the first-frost date. For transplanted crops (CSU days are from transplant) the result is the latest transplant date; seeds go in CSU's transplant-age weeks earlier. We add no harvest period, so these dates give you a first harvest by the first frost, not a long harvest.

Month-by-month: what to plant in Parker

What to plant in Parker in February

• Start broccoli seeds indoors (Feb 26 – Mar 12)
• Start cabbage seeds indoors (Feb 26 – Mar 12)

What to plant in Parker in March

• Start cauliflower seeds indoors (Mar 12–26)
• Start eggplant seeds indoors (Mar 26 – Apr 16)
• Start broccoli seeds indoors (Feb 26 – Mar 12)
• Start cabbage seeds indoors (Feb 26 – Mar 12)

What to plant in Parker in April

• Start pepper seeds indoors (Apr 2–16)
• Onions (dry, from sets): plant sets outdoors (Apr 11 – May 9)
• Peas: direct sow outdoors (Apr 11 – May 9)
• Lettuce (leaf): direct sow outdoors (Apr 11 – May 9)
• Broccoli: transplant outdoors (Apr 11 – May 9)
• Cabbage: transplant outdoors (Apr 11 – May 9)
• Kohlrabi: direct sow outdoors (Apr 11 – May 9)
• Green onions: direct sow outdoors (Apr 11 – May 9)
• Radishes: direct sow outdoors (Apr 11 – May 9)
• Spinach: direct sow outdoors (Apr 11 – May 9)
• Turnips: direct sow outdoors (Apr 11 – May 9)
• Potatoes: plant (seed pieces) outdoors (Apr 25 – May 23)
• Carrots: direct sow outdoors (Apr 25 – May 23)
• Cauliflower: transplant outdoors (Apr 25 – May 23)
• Beets: direct sow outdoors (Apr 25 – May 23)
• Swiss chard: direct sow outdoors (Apr 25 – May 23)
• Parsnips: direct sow outdoors (Apr 25 – May 23)
• Start eggplant seeds indoors (Mar 26 – Apr 16)

What to plant in Parker in May

• Start tomato seeds indoors (May 7–21)
• Start cabbage seeds indoors for a fall crop (May 8–22)
• Beans (snap): direct sow outdoors (May 9–23)
• Summer squash: direct sow outdoors (May 9–23)
• Sweet corn: direct sow outdoors (May 9–23)
• Cucumbers: direct sow outdoors (May 9–23)
• Peppers: transplant outdoors (May 23 – Jun 6)
• Eggplant: transplant outdoors (May 23 – Jun 6)
• Cantaloupe: direct sow outdoors (May 23 – Jun 6)
• Watermelon: direct sow outdoors (May 23 – Jun 6)
• Winter squash: direct sow outdoors (May 23 – Jun 6)
• Start broccoli seeds indoors for a fall crop (May 28 – Jun 11)
• Onions (dry, from sets): plant sets outdoors (Apr 11 – May 9)
• Peas: direct sow outdoors (Apr 11 – May 9)
• Lettuce (leaf): direct sow outdoors (Apr 11 – May 9)
• Broccoli: transplant outdoors (Apr 11 – May 9)
• Cabbage: transplant outdoors (Apr 11 – May 9)
• Kohlrabi: direct sow outdoors (Apr 11 – May 9)
• Green onions: direct sow outdoors (Apr 11 – May 9)
• Radishes: direct sow outdoors (Apr 11 – May 9)
• Spinach: direct sow outdoors (Apr 11 – May 9)
• Turnips: direct sow outdoors (Apr 11 – May 9)
• Potatoes: plant (seed pieces) outdoors (Apr 25 – May 23)
• Carrots: direct sow outdoors (Apr 25 – May 23)
• Cauliflower: transplant outdoors (Apr 25 – May 23)
• Beets: direct sow outdoors (Apr 25 – May 23)
• Swiss chard: direct sow outdoors (Apr 25 – May 23)
• Parsnips: direct sow outdoors (Apr 25 – May 23)

What to plant in Parker in June

• Tomatoes: transplant outdoors (Jun 25)
• Last day to set out cabbage transplants for a fall harvest (by Jun 26)
• Peppers: transplant outdoors (May 23 – Jun 6)
• Eggplant: transplant outdoors (May 23 – Jun 6)
• Cantaloupe: direct sow outdoors (May 23 – Jun 6)
• Watermelon: direct sow outdoors (May 23 – Jun 6)
• Winter squash: direct sow outdoors (May 23 – Jun 6)
• Start broccoli seeds indoors for a fall crop (May 28 – Jun 11)

What to plant in Parker in July

• Last day to sow beans (snap) for a fall harvest (by Jul 7)
• Last day to sow carrots for a fall harvest (by Jul 11)
• Last day to sow cucumbers for a fall harvest (by Jul 12)
• Last day to sow peas for a fall harvest (by Jul 16)
• Last day to set out broccoli transplants for a fall harvest (by Jul 16)
• Last day to sow summer squash for a fall harvest (by Jul 17)
• Last day to sow lettuce (leaf) for a fall harvest (by Jul 21)
• Last day to sow green onions for a fall harvest (by Jul 21)
• Last day to sow beets for a fall harvest (by Jul 21)
• Last day to sow swiss chard for a fall harvest (by Jul 21)
• Last day to sow kohlrabi for a fall harvest (by Jul 31)
• Last day to sow turnips for a fall harvest (by Jul 31)

What to plant in Parker in August

• Last day to sow spinach for a fall harvest (by Aug 10)
• Last day to sow radishes for a fall harvest (by Aug 20)

What to plant in Parker in October

• Plant garlic cloves (Oct 1–14)

Crop-by-crop notes

When to plant tomatoes in Parker

Very tender crop. CSU Extension's rules are to set tomatoes out at least 2 weeks after the average last frost and only once nights are above 52°F. In Parker, the frost rule alone would allow about May 23, but the average nightly low at Parker isn't above 52°F until Jun 25, so the night rule sets the date at every risk level: about Jun 25. Start seeds indoors May 7–21, 5–7 weeks before transplanting on Jun 25. Below 55°F at night, fruit set suffers (CSU). At Parker, the normal low reaches 55°F on Jul 11. Set out on Jun 25, tomato plants would start producing around Aug 29, based on CSU's typical 65 days from transplant to harvest. That leaves 35 days before the typical first frost (Oct 3).

When to plant peppers in Parker

Very tender crop. Following CSU Extension's rule (2+ weeks after the average last frost), set peppers out around May 23 with the typical date, May 28 for a balanced choice, or Jun 6 with the safer 10% date. Sow seeds indoors Apr 2–16, 6–8 weeks before transplanting on May 28. Below 55°F at night, fruit set suffers (CSU). At Parker, the normal low reaches 55°F on Jul 11. CSU's typical time from transplant to harvest for pepper plants is 70 days. Set out on May 28, they would start producing around Aug 6, 58 days before the typical first frost (Oct 3).

When to plant potatoes in Parker

Semi-hardy crop. CSU says potatoes can be planted as early as 0–2 weeks before the average last frost, in soil of at least 45°F. In Parker, that's roughly Apr 25 – May 9 going by the typical date, or May 9–23 going by the safer date.

When to plant onions (dry, from sets) in Parker

Hardy crop. CSU says onions (dry, from sets) can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 35°F. In Parker, that's roughly Apr 11–25 going by the typical date, or Apr 25 – May 9 going by the safer date.

When to plant peas in Parker

Hardy crop. CSU says peas can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 40°F. In Parker, that's roughly Apr 11–25 going by the typical date, or Apr 25 – May 9 going by the safer date. For fall, sow by Jul 16 (Jul 4 to be safe), which is 79 days before the first-frost date.

When to plant lettuce (leaf) in Parker

Hardy crop. CSU says lettuce (leaf) can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 35°F. In Parker, that's roughly Apr 11–25 going by the typical date, or Apr 25 – May 9 going by the safer date. For fall, sow by Jul 21 (Jul 9 to be safe), which is 74 days before the first-frost date.

When to plant carrots in Parker

Semi-hardy crop. CSU allows planting carrots as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Parker, that's roughly Apr 25 – May 9 by the typical date or May 9–23 by the safer date. For a fall crop, sow by Jul 11, or by Jun 29 to be safe. That's 84 days back from the first-frost date.

When to plant beans (snap) in Parker

Tender crop. CSU says to sow beans (snap) around the average last frost, about May 9 in Parker. If you want only a 1-in-10 chance of a later 32°F night, wait until May 23. Seeds need soil of at least 55°F. For a fall crop, sow by Jul 7, or by Jun 25 to be safe. That's 88 days back from the first-frost date.

When to plant summer squash in Parker

Tender crop. CSU says to sow summer squash around the average last frost, about May 9 in Parker. If you want only a 1-in-10 chance of a later 32°F night, wait until May 23. Seeds need soil of at least 60°F. For fall, count back 78 days from the first-frost date. That means sowing by Jul 17, or by Jul 5 to be safe.

When to plant broccoli in Parker

Hardy crop. CSU says broccoli can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 40°F. In Parker, that's roughly Apr 11–25 going by the typical date, or Apr 25 – May 9 going by the safer date. Using CSU's typical 65 days from transplant to harvest, broccoli plants set out on Apr 16 would start producing around Jun 20. That's 105 days before the typical first frost (Oct 3). For a fall harvest of broccoli, get transplants in the ground by Jul 16 (UNL Extension count-back from the typical first frost, Oct 3, with CSU's 65 days from transplant to harvest). To raise your own, sow seeds May 28 – Jun 11, 5–7 weeks ahead (CSU).

When to plant cabbage in Parker

Hardy crop. Per CSU, cabbage can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 40°F. For Parker, that works out to roughly Apr 11–25 (typical date) or Apr 25 – May 9 (safer date). CSU's typical time from transplant to harvest for cabbage plants is 85 days. Set out on Apr 16, they would start producing around Jul 10, 85 days before the typical first frost (Oct 3). For a fall harvest of cabbage, get transplants in the ground by Jun 26 (UNL Extension count-back from the typical first frost, Oct 3, with CSU's 85 days from transplant to harvest). To raise your own, sow seeds May 8–22, 5–7 weeks ahead (CSU).

When to plant cauliflower in Parker

Semi-hardy crop. CSU says cauliflower can be planted as early as 0–2 weeks before the average last frost, in soil of at least 40°F. In Parker, that's roughly Apr 25 – May 9 going by the typical date, or May 9–23 going by the safer date.

When to plant kohlrabi in Parker

Hardy crop. CSU says kohlrabi can go in as early as 2–4 weeks before the average last frost: roughly Apr 11–25 in Parker using the typical date, or Apr 25 – May 9 using the safer one. Wait until the soil can be worked and is at least 40°F. For a fall crop, sow by Jul 31, or by Jul 19 to be safe. That's 64 days back from the first-frost date.

When to plant green onions in Parker

Hardy crop. CSU says green onions can go in as early as 2–4 weeks before the average last frost: roughly Apr 11–25 in Parker using the typical date, or Apr 25 – May 9 using the safer one. Wait until the soil can be worked and is at least 35°F. For a fall crop, sow by Jul 21, or by Jul 9 to be safe. That's 74 days back from the first-frost date.

When to plant radishes in Parker

Hardy crop. CSU says radishes can go in as early as 2–4 weeks before the average last frost: roughly Apr 11–25 in Parker using the typical date, or Apr 25 – May 9 using the safer one. Wait until the soil can be worked and is at least 40°F. For a fall crop, sow by Aug 20, or by Aug 8 to be safe. That's 44 days back from the first-frost date.

When to plant spinach in Parker

Hardy crop. CSU says spinach can go in as early as 2–4 weeks before the average last frost: roughly Apr 11–25 in Parker using the typical date, or Apr 25 – May 9 using the safer one. Wait until the soil can be worked and is at least 40°F. For a fall crop, sow by Aug 10, or by Jul 29 to be safe. That's 54 days back from the first-frost date.

When to plant turnips in Parker

Hardy crop. Per CSU, turnips can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 40°F. For Parker, that works out to roughly Apr 11–25 (typical date) or Apr 25 – May 9 (safer date). For fall, count back 64 days from the first-frost date. That means sowing by Jul 31, or by Jul 19 to be safe.

When to plant beets in Parker

Semi-hardy crop. CSU says beets can be planted as early as 0–2 weeks before the average last frost, in soil of at least 40°F. In Parker, that's roughly Apr 25 – May 9 going by the typical date, or May 9–23 going by the safer date. For fall, count back 74 days from the first-frost date. That means sowing by Jul 21, or by Jul 9 to be safe.

When to plant swiss chard in Parker

Semi-hardy crop. CSU allows planting swiss chard as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Parker, that's roughly Apr 25 – May 9 by the typical date or May 9–23 by the safer date. For a fall crop, sow by Jul 21, or by Jul 9 to be safe. That's 74 days back from the first-frost date.

When to plant parsnips in Parker

Semi-hardy crop. CSU says parsnips can be planted as early as 0–2 weeks before the average last frost, in soil of at least 35°F. In Parker, that's roughly Apr 25 – May 9 going by the typical date, or May 9–23 going by the safer date.

When to plant sweet corn in Parker

Tender crop. Sow sweet corn around the average last frost, per CSU: about May 9 in Parker. Waiting until May 23 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 50°F.

When to plant cucumbers in Parker

Tender crop. CSU's timing for cucumbers is around the average last frost, which is about May 9 in Parker. For only a 1-in-10 chance of a later 32°F night, hold off until May 23. Seeds want soil at 60°F or warmer. For a fall crop, sow by Jul 12, or by Jun 30 to be safe. That's 83 days back from the first-frost date.

When to plant eggplant in Parker

Very tender crop. CSU Extension's rule is to set eggplant out at least 2 weeks after the average last frost. That's about May 23 using the typical date, May 28 as a balanced choice, or Jun 6 if you go by the safer 10% date. Start seeds indoors Mar 26 – Apr 16, 6–9 weeks before transplanting on May 28. CSU's typical time from transplant to harvest for eggplant plants is 60 days. Set out on May 28, they would start producing around Jul 27, 68 days before the typical first frost (Oct 3).

When to plant cantaloupe in Parker

Very tender crop. Following CSU Extension's rule of 2+ weeks after the average last frost, plant cantaloupe around May 23 at the earliest, May 28 as a balanced choice, or Jun 6 to be safe. CSU's minimum soil temperature is 60°F.

When to plant watermelon in Parker

Very tender crop. Following CSU Extension's rule of 2+ weeks after the average last frost, plant watermelon around May 23 at the earliest, May 28 as a balanced choice, or Jun 6 to be safe. CSU's minimum soil temperature is 60°F.

When to plant winter squash in Parker

Very tender crop. Following CSU Extension's rule of 2+ weeks after the average last frost, plant winter squash around May 23 at the earliest, May 28 as a balanced choice, or Jun 6 to be safe. CSU's minimum soil temperature is 60°F.

When to plant garlic in Parker

Plant garlic in early October, before October 15 (Oct 1–14), per CSU Extension's Colorado guidance. The window is fixed statewide and isn't based on frost data. At Parker, the typical first hard freeze (28°F) comes on Oct 12, no later than the window's last day.

How these dates are calculated

CSU states its spring rules relative to “the average last spring frost.” We use the 50% date as that average and also show the 30% and 10% anchors. See the methodology for details and limitations.

FAQ

When should I start seeds indoors in Parker?

Start tomatoes May 7–21 and peppers Apr 2–16. Both dates count back from a balanced (30%-risk) transplant date using CSU's transplant ages.

When should I plant tomatoes outside in Parker?

About Jun 25, at every risk level. CSU wants tomatoes out 2+ weeks after the average last frost (that rule alone gives about May 23 here) and nights above 52°F. At Parker, the average nightly low first rises above 52°F on Jun 25, later than the frost-rule date, so the night rule sets the date.

What can I plant in Parker in the fall?

Counting back from the typical first frost (Oct 3) with UNL Extension's method: peas by Jul 16; lettuce (leaf) by Jul 21; carrots by Jul 11; beans (snap) by Jul 7; summer squash by Jul 17; broccoli by Jul 16 (transplants); cabbage by Jun 26 (transplants); kohlrabi by Jul 31; green onions by Jul 21; radishes by Aug 20; spinach by Aug 10; turnips by Jul 31; beets by Jul 21; swiss chard by Jul 21; cucumbers by Jul 12. Garlic goes in Oct 1–14.

When should I plant garlic in Parker?

In early October, before October 15 (Oct 1–14), per CSU Extension's Colorado guidance.

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