When to Plant Sweet Potatoes in Fort Collins, CO
Published: April 24, 2026
Sweet Potato Planting Dates for Fort Collins, CO
| Start seeds indoors | Year-round |
| Last frost (average) | March 30 |
| Direct sow outdoors | April 20–30 |
| Minimum soil temperature | 60°F |
| Expect first harvest | July 19 – August 18 |
| First fall frost (average) | November 1 |
⚠ Plant sweet potato slips 2–3 weeks after last frost when soil is consistently above 60°F. Needs 90–120 days of warm weather. Best in Zones 5–11.
Best Sweet Potato Varieties for Fort Collins, CO
Consult a Fort Collins-area nursery or your state extension office for sweet potato varieties proven in Zone 6a.
Growing Sweet Potatoes in Fort Collins
Fort Collins sits in Zone 6a, with an average last frost of March 30 and first fall frost around November 1 — giving a 216-day frost-free growing season. Warm-season crops like sweet potato need soil at 60°F or above before transplanting; Fort Collins's frost calendar puts that window clearly in the late-spring to early-fall range.
Fort Collins's moderate climate supports sweet potato on the standard transplant calendar with minimal special accommodation. Succession planting — sowing fresh seeds or setting new transplants every 2–3 weeks through spring — stretches the harvest window and gives you a backup crop if pests hit the first planting.
Fort Collins's well-draining loam soils are among the best for sweet potato growing — focus on annual organic matter additions (2 to 3 inches of compost) and consistent moisture during drier months. Water sweet potato at 1 inches per week; loam holds moisture evenly without the drought-crack cycle of heavy clay or the rapid-drain losses of pure sand.
Sweet Potato Calendar for Fort Collins
| Month | Task |
|---|---|
| Year | Start seeds indoors under grow lights |
| March | Last frost — soil warming, prepare bed |
| April | Direct sow seeds into warm soil |
| July | Expect first harvest window to open |
| November | First fall frost — harvest remaining, end of outdoor season |
Sweet Potato Tips for Fort Collins Gardeners
- •Order slips in early spring from a seed company; plant within 24 hours of arrival in pre-warmed soil.
- •Form raised ridges or mounds 10 inches tall — sweet potatoes size up best in loose, warm, well-drained soil.
- •Succession plant sweet potato in Fort Collins every 2–3 weeks through spring to extend the harvest window into summer.
Common Sweet Potato Pests in Fort Collins
- •Sweet Potato Weevil — peaks July in Zone 6a (active May–September); monitor closely during peak season and treat early.
- •Wireworm — peaks July in Zone 6a (active May–September); orange-brown beetle larvae in soil; trap with cut potato pieces buried in soil.
- •Flea Beetle — peaks July in Zone 6a (active May–September); tiny black beetles that riddle leaves with holes; row covers protect seedlings.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Sweet Potatoes in Fort Collins
In Fort Collins's moderate climate, Bush Bean and Pea are the most beneficial plants to grow alongside sweet potato. Bush Bean improves nearby plant health and pest resistance. Keep sweet potato away from Squash — it competes for nutrients or shares pest pressure.
Frequently Asked Questions
When should I plant sweet potato in Fort Collins, CO?
In Fort Collins (Zone 6a), direct sow sweet potato around April 20–30. Soil must be at 60°F or warmer at 2-inch depth before sowing — cold soil rots the seeds.
What zone is Fort Collins, CO for sweet potato growing?
Fort Collins is USDA Zone 6a. For sweet potato, this means a frost-free growing season of roughly 31 weeks running from March 30 to November 1. This is a comfortable window for warm-season crops like sweet potato — standard varieties work well.
When is sweet potato harvest season in Fort Collins?
Expect the first sweet potato harvest in Fort Collins around July 19, with harvest continuing through August 18. This is based on 90–120 days from transplant or direct sow.
How long does it take to grow sweet potato in Fort Collins, CO?
From transplant or direct sow to first harvest, sweet potato takes 90–120 days in Fort Collins's climate. Based on a typical planting date of April 20–30, expect your first harvest around July 19. Fort Collins's Zone 6a transition-zone climate produces maturity times right in the middle of the stated range.
What soil does sweet potato need in Fort Collins?
Fort Collins's loam soil is near-ideal for sweet potato. Work in 2–3 inches of compost before planting to boost organic matter and nutrient content. Minimal amendment is needed beyond that — loam holds moisture evenly without the drought-crack cycle of clay or the nutrient-loss issues of sandy soil.