Commerce City, CO Vegetable Planting Calendar

What to plant now in Commerce City

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 3, 50% risk), balanced = May 8 (30%), safe = May 16 (10%). For hardy crops the cell shows the CSU “as early as” window.

A soil thermometer helps here. CSU recommends checking soil temperature at 4 inches (6 inches for beans) before sowing. NOAA doesn't publish soil-temperature normals, so instead of a date, each crop shows CSU's minimum soil temperature.

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 Commerce City

What to plant in Commerce City in February

• Start broccoli seeds indoors (Feb 20 – Mar 6)
• Start cabbage seeds indoors (Feb 20 – Mar 6)

What to plant in Commerce City in March

• Start cauliflower seeds indoors (Mar 6–20)
• Start eggplant seeds indoors (Mar 20 – Apr 10)
• Start pepper seeds indoors (Mar 27 – Apr 10)
• Start broccoli seeds indoors (Feb 20 – Mar 6)
• Start cabbage seeds indoors (Feb 20 – Mar 6)

What to plant in Commerce City in April

• Onions (dry, from sets): plant sets outdoors (Apr 5 – May 2)
• Peas: direct sow outdoors (Apr 5 – May 2)
• Lettuce (leaf): direct sow outdoors (Apr 5 – May 2)
• Broccoli: transplant outdoors (Apr 5 – May 2)
• Cabbage: transplant outdoors (Apr 5 – May 2)
• Kohlrabi: direct sow outdoors (Apr 5 – May 2)
• Green onions: direct sow outdoors (Apr 5 – May 2)
• Radishes: direct sow outdoors (Apr 5 – May 2)
• Spinach: direct sow outdoors (Apr 5 – May 2)
• Turnips: direct sow outdoors (Apr 5 – May 2)
• Potatoes: plant (seed pieces) outdoors (Apr 19 – May 16)
• Carrots: direct sow outdoors (Apr 19 – May 16)
• Cauliflower: transplant outdoors (Apr 19 – May 16)
• Beets: direct sow outdoors (Apr 19 – May 16)
• Swiss chard: direct sow outdoors (Apr 19 – May 16)
• Parsnips: direct sow outdoors (Apr 19 – May 16)
• Start tomato seeds indoors (Apr 26 – May 10)
• Start eggplant seeds indoors (Mar 20 – Apr 10)
• Start pepper seeds indoors (Mar 27 – Apr 10)

What to plant in Commerce City in May

• Beans (snap): direct sow outdoors (May 3–16)
• Summer squash: direct sow outdoors (May 3–16)
• Sweet corn: direct sow outdoors (May 3–16)
• Cucumbers: direct sow outdoors (May 3–16)
• Start cabbage seeds indoors for a fall crop (May 12–26)
• Peppers: transplant outdoors (May 17–30)
• Eggplant: transplant outdoors (May 17–30)
• Cantaloupe: direct sow outdoors (May 17–30)
• Watermelon: direct sow outdoors (May 17–30)
• Winter squash: direct sow outdoors (May 17–30)
• Onions (dry, from sets): plant sets outdoors (Apr 5 – May 2)
• Peas: direct sow outdoors (Apr 5 – May 2)
• Lettuce (leaf): direct sow outdoors (Apr 5 – May 2)
• Broccoli: transplant outdoors (Apr 5 – May 2)
• Cabbage: transplant outdoors (Apr 5 – May 2)
• Kohlrabi: direct sow outdoors (Apr 5 – May 2)
• Green onions: direct sow outdoors (Apr 5 – May 2)
• Radishes: direct sow outdoors (Apr 5 – May 2)
• Spinach: direct sow outdoors (Apr 5 – May 2)
• Turnips: direct sow outdoors (Apr 5 – May 2)
• Potatoes: plant (seed pieces) outdoors (Apr 19 – May 16)
• Carrots: direct sow outdoors (Apr 19 – May 16)
• Cauliflower: transplant outdoors (Apr 19 – May 16)
• Beets: direct sow outdoors (Apr 19 – May 16)
• Swiss chard: direct sow outdoors (Apr 19 – May 16)
• Parsnips: direct sow outdoors (Apr 19 – May 16)
• Start tomato seeds indoors (Apr 26 – May 10)

What to plant in Commerce City in June

• Start broccoli seeds indoors for a fall crop (Jun 1–15)
• Tomatoes: transplant outdoors (Jun 14)
• Last day to set out cabbage transplants for a fall harvest (by Jun 30)

What to plant in Commerce City in July

• Last day to sow beans (snap) for a fall harvest (by Jul 11)
• Last day to sow carrots for a fall harvest (by Jul 15)
• Last day to sow cucumbers for a fall harvest (by Jul 16)
• Last day to sow peas for a fall harvest (by Jul 20)
• Last day to set out broccoli transplants for a fall harvest (by Jul 20)
• Last day to sow summer squash for a fall harvest (by Jul 21)
• Last day to sow lettuce (leaf) for a fall harvest (by Jul 25)
• Last day to sow green onions for a fall harvest (by Jul 25)
• Last day to sow beets for a fall harvest (by Jul 25)
• Last day to sow swiss chard for a fall harvest (by Jul 25)

What to plant in Commerce City in August

• Last day to sow kohlrabi for a fall harvest (by Aug 4)
• Last day to sow turnips for a fall harvest (by Aug 4)
• Last day to sow spinach for a fall harvest (by Aug 14)
• Last day to sow radishes for a fall harvest (by Aug 24)

What to plant in Commerce City in October

• Plant garlic cloves (Oct 1–14)

Crop-by-crop notes

When to plant tomatoes in Commerce City

Very tender crop. CSU Extension says to transplant tomatoes at least 2 weeks after the average last frost, with nights above 52°F. The frost rule alone would put Commerce City at about May 17, but the average nightly low at Brighton 3 SE isn't above 52°F until Jun 14, so the transplant date is about Jun 14 for the typical, balanced and safer choices alike. Start seeds indoors Apr 26 – May 10, 5–7 weeks before transplanting on Jun 14. Fruit set suffers when nights drop below 55°F (CSU). The normal low at Brighton 3 SE reaches 55°F on Jun 26. CSU's typical time from transplant to harvest for tomato plants is 65 days. Set out on Jun 14, they would start producing around Aug 18, 50 days before the typical first frost (Oct 7).

When to plant peppers in Commerce City

Very tender crop. Following CSU Extension's rule (2+ weeks after the average last frost), set peppers out around May 17 with the typical date, May 22 for a balanced choice, or May 30 with the safer 10% date. Sow seeds indoors Mar 27 – Apr 10, 6–8 weeks before transplanting on May 22. Below 55°F at night, fruit set suffers (CSU). At Brighton 3 SE, the normal low reaches 55°F on Jun 26. Set out on May 22, pepper plants would start producing around Jul 31, based on CSU's typical 70 days from transplant to harvest. That leaves 68 days before the typical first frost (Oct 7).

When to plant potatoes in Commerce City

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 Commerce City, that's roughly Apr 19 – May 3 going by the typical date, or May 2–16 going by the safer date.

When to plant onions (dry, from sets) in Commerce City

Hardy crop. CSU says onions (dry, from sets) can go in as early as 2–4 weeks before the average last frost: roughly Apr 5–19 in Commerce City using the typical date, or Apr 18 – May 2 using the safer one. Wait until the soil can be worked and is at least 35°F.

When to plant peas in Commerce City

Hardy crop. Per CSU, peas 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 Commerce City, that works out to roughly Apr 5–19 (typical date) or Apr 18 – May 2 (safer date). For fall, count back 79 days from the first-frost date. That means sowing by Jul 20, or by Jul 9 to be safe.

When to plant lettuce (leaf) in Commerce City

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 Commerce City, that's roughly Apr 5–19 going by the typical date, or Apr 18 – May 2 going by the safer date. For fall, sow by Jul 25 (Jul 14 to be safe), which is 74 days before the first-frost date.

When to plant carrots in Commerce City

Semi-hardy crop. CSU says carrots can be planted as early as 0–2 weeks before the average last frost, in soil of at least 40°F. In Commerce City, that's roughly Apr 19 – May 3 going by the typical date, or May 2–16 going by the safer date. For fall, sow by Jul 15 (Jul 4 to be safe), which is 84 days before the first-frost date.

When to plant beans (snap) in Commerce City

Tender crop. CSU's timing for beans (snap) is around the average last frost, which is about May 3 in Commerce City. For only a 1-in-10 chance of a later 32°F night, hold off until May 16. Seeds want soil at 55°F or warmer. For fall, count back 88 days from the first-frost date. That means sowing by Jul 11, or by Jun 30 to be safe.

When to plant summer squash in Commerce City

Tender crop. Sow summer squash around the average last frost, per CSU: about May 3 in Commerce City. Waiting until May 16 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 60°F. For a fall crop, sow by Jul 21, or by Jul 10 to be safe. That's 78 days back from the first-frost date.

When to plant broccoli in Commerce City

Hardy crop. CSU says broccoli can go in as early as 2–4 weeks before the average last frost: roughly Apr 5–19 in Commerce City using the typical date, or Apr 18 – May 2 using the safer one. Wait until the soil can be worked and is at least 40°F. CSU's typical time from transplant to harvest for broccoli plants is 65 days. Set out on Apr 10, they would start producing around Jun 14, 115 days before the typical first frost (Oct 7). For a fall harvest of broccoli, get transplants in the ground by Jul 20 (UNL Extension count-back from the typical first frost, Oct 7, with CSU's 65 days from transplant to harvest). To raise your own, sow seeds Jun 1–15, 5–7 weeks ahead (CSU).

When to plant cabbage in Commerce City

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 Commerce City, that works out to roughly Apr 5–19 (typical date) or Apr 18 – May 2 (safer date). Using CSU's typical 85 days from transplant to harvest, cabbage plants set out on Apr 10 would start producing around Jul 4. That's 95 days before the typical first frost (Oct 7). Fall cabbage: set transplants out by Jun 30. The date counts back from the typical first frost (Oct 7) by UNL Extension's method, using CSU's 85 days from transplant to harvest. Home-grown transplants need seeds started May 12–26 (CSU: 5–7 weeks).

When to plant cauliflower in Commerce City

Semi-hardy crop. CSU allows planting cauliflower as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Commerce City, that's roughly Apr 19 – May 3 by the typical date or May 2–16 by the safer date.

When to plant kohlrabi in Commerce City

Hardy crop. CSU says kohlrabi 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 Commerce City, that's roughly Apr 5–19 going by the typical date, or Apr 18 – May 2 going by the safer date. For a fall crop, sow by Aug 4, or by Jul 24 to be safe. That's 64 days back from the first-frost date.

When to plant green onions in Commerce City

Hardy crop. CSU says green onions can go in as early as 2–4 weeks before the average last frost: roughly Apr 5–19 in Commerce City using the typical date, or Apr 18 – May 2 using the safer one. Wait until the soil can be worked and is at least 35°F. For a fall crop, sow by Jul 25, or by Jul 14 to be safe. That's 74 days back from the first-frost date.

When to plant radishes in Commerce City

Hardy crop. CSU says radishes can go in as early as 2–4 weeks before the average last frost: roughly Apr 5–19 in Commerce City using the typical date, or Apr 18 – May 2 using the safer one. Wait until the soil can be worked and is at least 40°F. For fall, sow by Aug 24 (Aug 13 to be safe), which is 44 days before the first-frost date.

When to plant spinach in Commerce City

Hardy crop. CSU says spinach 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 Commerce City, that's roughly Apr 5–19 going by the typical date, or Apr 18 – May 2 going by the safer date. For a fall crop, sow by Aug 14, or by Aug 3 to be safe. That's 54 days back from the first-frost date.

When to plant turnips in Commerce City

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 Commerce City, that works out to roughly Apr 5–19 (typical date) or Apr 18 – May 2 (safer date). For fall, sow by Aug 4 (Jul 24 to be safe), which is 64 days before the first-frost date.

When to plant beets in Commerce City

Semi-hardy crop. CSU allows planting beets as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Commerce City, that's roughly Apr 19 – May 3 by the typical date or May 2–16 by the safer date. For a fall crop, sow by Jul 25, or by Jul 14 to be safe. That's 74 days back from the first-frost date.

When to plant swiss chard in Commerce City

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 Commerce City, that's roughly Apr 19 – May 3 by the typical date or May 2–16 by the safer date. For fall, sow by Jul 25 (Jul 14 to be safe), which is 74 days before the first-frost date.

When to plant parsnips in Commerce City

Semi-hardy crop. Per CSU, parsnips can go in as early as 0–2 weeks before the average last frost: roughly Apr 19 – May 3 in Commerce City (typical date) or May 2–16 (safer date). The soil should be at least 35°F.

When to plant sweet corn in Commerce City

Tender crop. Sow sweet corn around the average last frost, per CSU: about May 3 in Commerce City. Waiting until May 16 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 Commerce City

Tender crop. Sow cucumbers around the average last frost, per CSU: about May 3 in Commerce City. Waiting until May 16 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 60°F. For fall, sow by Jul 16 (Jul 5 to be safe), which is 83 days before the first-frost date.

When to plant eggplant in Commerce City

Very tender crop. Following CSU Extension's rule (2+ weeks after the average last frost), set eggplant out around May 17 with the typical date, May 22 for a balanced choice, or May 30 with the safer 10% date. Sow seeds indoors Mar 20 – Apr 10, 6–9 weeks before transplanting on May 22. CSU's typical time from transplant to harvest for eggplant plants is 60 days. Set out on May 22, they would start producing around Jul 21, 78 days before the typical first frost (Oct 7).

When to plant cantaloupe in Commerce City

Very tender crop. Following CSU Extension's rule of 2+ weeks after the average last frost, plant cantaloupe around May 17 at the earliest, May 22 as a balanced choice, or May 30 to be safe. CSU's minimum soil temperature is 60°F.

When to plant watermelon in Commerce City

Very tender crop. CSU Extension says to plant watermelon 2+ weeks after the average last frost: about May 17 (typical date), May 22 (balanced) or May 30 (safer 10% date). Wait for soil of at least 60°F.

When to plant winter squash in Commerce City

Very tender crop. CSU Extension's rule is to plant winter squash at least 2 weeks after the average last frost. That's about May 17 using the typical date, May 22 as a balanced choice, or May 30 if you go by the safer 10% date. Seeds need soil of at least 60°F.

When to plant garlic in Commerce City

For garlic, CSU Extension's Colorado guidance gives a fixed statewide window: early October, before October 15 (Oct 1–14). It isn't computed from frost data. At Brighton 3 SE, the typical first 28°F hard freeze comes on Oct 16, 2 days after the window ends.

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 Commerce City?

Start tomatoes Apr 26 – May 10 and peppers Mar 27 – Apr 10. Both dates count back from a balanced (30%-risk) transplant date using CSU's transplant ages.

When should I plant tomatoes outside in Commerce City?

About Jun 14 at every risk level, because the night rule decides it. CSU wants nights above 52°F at transplant, and the average nightly low at Brighton 3 SE first rises above 52°F on Jun 14. CSU's frost rule (2+ weeks after the average last frost) would allow about May 17 here.

What can I plant in Commerce City in the fall?

Based on UNL Extension's count-back from the typical first frost (Oct 7), sow peas by Jul 20; lettuce (leaf) by Jul 25; carrots by Jul 15; beans (snap) by Jul 11; summer squash by Jul 21; broccoli by Jul 20 (transplants); cabbage by Jun 30 (transplants); kohlrabi by Aug 4; green onions by Jul 25; radishes by Aug 24; spinach by Aug 14; turnips by Aug 4; beets by Jul 25; swiss chard by Jul 25; cucumbers by Jul 16. Garlic goes in Oct 1–14.

When should I plant garlic in Commerce City?

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

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