Fort Collins, CO Vegetable Planting Calendar

What to plant now in Fort Collins

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 2, 50% risk), balanced = May 7 (30%), safe = May 14 (10%). For hardy crops the cell shows the CSU “as early as” window.

Before sowing, check the soil too. CSU recommends taking its temperature at 4 inches (6 inches for beans). Since NOAA publishes no soil-temperature normals, we give CSU's minimum soil temperature for each crop rather than 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 Fort Collins

What to plant in Fort Collins in February

• Start broccoli seeds indoors (Feb 19 – Mar 5)
• Start cabbage seeds indoors (Feb 19 – Mar 5)

What to plant in Fort Collins in March

• Start cauliflower seeds indoors (Mar 5–19)
• Start eggplant seeds indoors (Mar 19 – Apr 9)
• Start pepper seeds indoors (Mar 26 – Apr 9)
• Start broccoli seeds indoors (Feb 19 – Mar 5)
• Start cabbage seeds indoors (Feb 19 – Mar 5)

What to plant in Fort Collins in April

• Onions (dry, from sets): plant sets outdoors (Apr 4–30)
• Peas: direct sow outdoors (Apr 4–30)
• Lettuce (leaf): direct sow outdoors (Apr 4–30)
• Broccoli: transplant outdoors (Apr 4–30)
• Cabbage: transplant outdoors (Apr 4–30)
• Kohlrabi: direct sow outdoors (Apr 4–30)
• Green onions: direct sow outdoors (Apr 4–30)
• Radishes: direct sow outdoors (Apr 4–30)
• Spinach: direct sow outdoors (Apr 4–30)
• Turnips: direct sow outdoors (Apr 4–30)
• Potatoes: plant (seed pieces) outdoors (Apr 18 – May 14)
• Carrots: direct sow outdoors (Apr 18 – May 14)
• Cauliflower: transplant outdoors (Apr 18 – May 14)
• Beets: direct sow outdoors (Apr 18 – May 14)
• Swiss chard: direct sow outdoors (Apr 18 – May 14)
• Parsnips: direct sow outdoors (Apr 18 – May 14)
• Start tomato seeds indoors (Apr 25 – May 9)
• Start eggplant seeds indoors (Mar 19 – Apr 9)
• Start pepper seeds indoors (Mar 26 – Apr 9)

What to plant in Fort Collins in May

• Beans (snap): direct sow outdoors (May 2–14)
• Summer squash: direct sow outdoors (May 2–14)
• Sweet corn: direct sow outdoors (May 2–14)
• Cucumbers: direct sow outdoors (May 2–14)
• Start cabbage seeds indoors for a fall crop (May 12–26)
• Peppers: transplant outdoors (May 16–28)
• Eggplant: transplant outdoors (May 16–28)
• Cantaloupe: direct sow outdoors (May 16–28)
• Watermelon: direct sow outdoors (May 16–28)
• Winter squash: direct sow outdoors (May 16–28)
• Potatoes: plant (seed pieces) outdoors (Apr 18 – May 14)
• Carrots: direct sow outdoors (Apr 18 – May 14)
• Cauliflower: transplant outdoors (Apr 18 – May 14)
• Beets: direct sow outdoors (Apr 18 – May 14)
• Swiss chard: direct sow outdoors (Apr 18 – May 14)
• Parsnips: direct sow outdoors (Apr 18 – May 14)
• Start tomato seeds indoors (Apr 25 – May 9)

What to plant in Fort Collins in June

• Start broccoli seeds indoors for a fall crop (Jun 1–15)
• Tomatoes: transplant outdoors (Jun 13)
• Last day to set out cabbage transplants for a fall harvest (by Jun 30)

What to plant in Fort Collins 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 Fort Collins 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 Fort Collins in October

• Plant garlic cloves (Oct 1–14)

Crop-by-crop notes

When to plant tomatoes in Fort Collins

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 Fort Collins at about May 16, but the average nightly low at Fort Collins isn't above 52°F until Jun 13, so the transplant date is about Jun 13 for the typical, balanced and safer choices alike. Start seeds indoors Apr 25 – May 9, 5–7 weeks before transplanting on Jun 13. Fruit set suffers when nights drop below 55°F (CSU). The normal low at Fort Collins reaches 55°F on Jun 24. Set out on Jun 13, tomato plants would start producing around Aug 17, based on CSU's typical 65 days from transplant to harvest. That leaves 51 days before the typical first frost (Oct 7).

When to plant peppers in Fort Collins

Very tender crop. CSU Extension's rule is 2+ weeks after the average last frost, which puts peppers outside around May 16 (typical date), May 21 (balanced) or May 28 (safer 10% date). Start seeds indoors Mar 26 – Apr 9, 6–8 weeks ahead of transplanting on May 21. Below 55°F at night, fruit set suffers (CSU). At Fort Collins, the normal low reaches 55°F on Jun 24. Set out on May 21, pepper plants would start producing around Jul 30, based on CSU's typical 70 days from transplant to harvest. That leaves 69 days before the typical first frost (Oct 7).

When to plant potatoes in Fort Collins

Semi-hardy crop. Per CSU, potatoes can go in as early as 0–2 weeks before the average last frost: roughly Apr 18 – May 2 in Fort Collins (typical date) or Apr 30 – May 14 (safer date). The soil should be at least 45°F.

When to plant onions (dry, from sets) in Fort Collins

Hardy crop. Per CSU, onions (dry, from sets) can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 35°F. For Fort Collins, that works out to roughly Apr 4–18 (typical date) or Apr 16–30 (safer date).

When to plant peas in Fort Collins

Hardy crop. CSU says peas can go in as early as 2–4 weeks before the average last frost: roughly Apr 4–18 in Fort Collins using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 40°F. For fall, count back 79 days from the first-frost date. That means sowing by Jul 20, or by Jul 7 to be safe.

When to plant lettuce (leaf) in Fort Collins

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 Fort Collins, that's roughly Apr 4–18 going by the typical date, or Apr 16–30 going by the safer date. For fall, count back 74 days from the first-frost date. That means sowing by Jul 25, or by Jul 12 to be safe.

When to plant carrots in Fort Collins

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 Fort Collins, that's roughly Apr 18 – May 2 by the typical date or Apr 30 – May 14 by the safer date. For a fall crop, sow by Jul 15, or by Jul 2 to be safe. That's 84 days back from the first-frost date.

When to plant beans (snap) in Fort Collins

Tender crop. CSU's timing for beans (snap) is around the average last frost, which is about May 2 in Fort Collins. For only a 1-in-10 chance of a later 32°F night, hold off until May 14. Seeds want soil at 55°F or warmer. For fall, sow by Jul 11 (Jun 28 to be safe), which is 88 days before the first-frost date.

When to plant summer squash in Fort Collins

Tender crop. CSU says to sow summer squash around the average last frost, about May 2 in Fort Collins. If you want only a 1-in-10 chance of a later 32°F night, wait until May 14. Seeds need soil of at least 60°F. For a fall crop, sow by Jul 21, or by Jul 8 to be safe. That's 78 days back from the first-frost date.

When to plant broccoli in Fort Collins

Hardy crop. Per CSU, broccoli 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 Fort Collins, that works out to roughly Apr 4–18 (typical date) or Apr 16–30 (safer date). Using CSU's typical 65 days from transplant to harvest, broccoli plants set out on Apr 9 would start producing around Jun 13. That's 116 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 Fort Collins

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 Fort Collins, that works out to roughly Apr 4–18 (typical date) or Apr 16–30 (safer date). Set out on Apr 9, cabbage plants would start producing around Jul 3, based on CSU's typical 85 days from transplant to harvest. That leaves 96 days before the typical first frost (Oct 7). For a fall crop, set cabbage transplants out by Jun 30. That's UNL Extension's count-back from the typical first frost (Oct 7), using CSU's 85 days from transplant to harvest. If you grow your own transplants, start seeds May 12–26 (CSU: 5–7 weeks to transplant size).

When to plant cauliflower in Fort Collins

Semi-hardy crop. Per CSU, cauliflower can go in as early as 0–2 weeks before the average last frost: roughly Apr 18 – May 2 in Fort Collins (typical date) or Apr 30 – May 14 (safer date). The soil should be at least 40°F.

When to plant kohlrabi in Fort Collins

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 Fort Collins, that's roughly Apr 4–18 going by the typical date, or Apr 16–30 going by the safer date. For fall, count back 64 days from the first-frost date. That means sowing by Aug 4, or by Jul 22 to be safe.

When to plant green onions in Fort Collins

Hardy crop. Per CSU, green onions can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 35°F. For Fort Collins, that works out to roughly Apr 4–18 (typical date) or Apr 16–30 (safer date). For fall, sow by Jul 25 (Jul 12 to be safe), which is 74 days before the first-frost date.

When to plant radishes in Fort Collins

Hardy crop. Per CSU, radishes 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 Fort Collins, that works out to roughly Apr 4–18 (typical date) or Apr 16–30 (safer date). For a fall crop, sow by Aug 24, or by Aug 11 to be safe. That's 44 days back from the first-frost date.

When to plant spinach in Fort Collins

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 Fort Collins, that's roughly Apr 4–18 going by the typical date, or Apr 16–30 going by the safer date. For fall, sow by Aug 14 (Aug 1 to be safe), which is 54 days before the first-frost date.

When to plant turnips in Fort Collins

Hardy crop. CSU says turnips 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 Fort Collins, that's roughly Apr 4–18 going by the typical date, or Apr 16–30 going by the safer date. For fall, sow by Aug 4 (Jul 22 to be safe), which is 64 days before the first-frost date.

When to plant beets in Fort Collins

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 Fort Collins, that's roughly Apr 18 – May 2 going by the typical date, or Apr 30 – May 14 going by the safer date. For fall, count back 74 days from the first-frost date. That means sowing by Jul 25, or by Jul 12 to be safe.

When to plant swiss chard in Fort Collins

Semi-hardy crop. Per CSU, swiss chard can go in as early as 0–2 weeks before the average last frost: roughly Apr 18 – May 2 in Fort Collins (typical date) or Apr 30 – May 14 (safer date). The soil should be at least 40°F. For fall, sow by Jul 25 (Jul 12 to be safe), which is 74 days before the first-frost date.

When to plant parsnips in Fort Collins

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 Fort Collins, that's roughly Apr 18 – May 2 going by the typical date, or Apr 30 – May 14 going by the safer date.

When to plant sweet corn in Fort Collins

Tender crop. CSU says to sow sweet corn around the average last frost, about May 2 in Fort Collins. If you want only a 1-in-10 chance of a later 32°F night, wait until May 14. Seeds need soil of at least 50°F.

When to plant cucumbers in Fort Collins

Tender crop. CSU says to sow cucumbers around the average last frost, about May 2 in Fort Collins. If you want only a 1-in-10 chance of a later 32°F night, wait until May 14. Seeds need soil of at least 60°F. For fall, sow by Jul 16 (Jul 3 to be safe), which is 83 days before the first-frost date.

When to plant eggplant in Fort Collins

Very tender crop. CSU Extension's rule is 2+ weeks after the average last frost, which puts eggplant outside around May 16 (typical date), May 21 (balanced) or May 28 (safer 10% date). Start seeds indoors Mar 19 – Apr 9, 6–9 weeks ahead of transplanting on May 21. Using CSU's typical 60 days from transplant to harvest, eggplant plants set out on May 21 would start producing around Jul 20. That's 79 days before the typical first frost (Oct 7).

When to plant cantaloupe in Fort Collins

Very tender crop. CSU Extension says to plant cantaloupe 2+ weeks after the average last frost: about May 16 (typical date), May 21 (balanced) or May 28 (safer 10% date). Wait for soil of at least 60°F.

When to plant watermelon in Fort Collins

Very tender crop. CSU Extension says to plant watermelon 2+ weeks after the average last frost: about May 16 (typical date), May 21 (balanced) or May 28 (safer 10% date). Wait for soil of at least 60°F.

When to plant winter squash in Fort Collins

Very tender crop. Following CSU Extension's rule of 2+ weeks after the average last frost, plant winter squash around May 16 at the earliest, May 21 as a balanced choice, or May 28 to be safe. CSU's minimum soil temperature is 60°F.

When to plant garlic in Fort Collins

CSU Extension's Colorado guidance is to plant garlic in early October, before October 15 (Oct 1–14). That's a fixed statewide window, not one computed from frost data. At Fort Collins, the typical first hard freeze (28°F) is Oct 17, 3 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 Fort Collins?

Tomatoes: Apr 25 – May 9. Peppers: Mar 26 – Apr 9. Both windows count back from a balanced (30%-risk) transplant date using CSU's transplant ages.

When should I plant tomatoes outside in Fort Collins?

About Jun 13 at every risk level, because the night rule decides it. CSU wants nights above 52°F at transplant, and the average nightly low at Fort Collins first rises above 52°F on Jun 13. CSU's frost rule (2+ weeks after the average last frost) would allow about May 16 here.

What can I plant in Fort Collins in the fall?

These sowing deadlines count back from the typical first frost (Oct 7) using UNL Extension's method: 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. Plant garlic Oct 1–14.

When should I plant garlic in Fort Collins?

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

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