When to Plant Cilantro in Colorado
You either love it or your genetics say no. For the cilantro lovers, it's an essential herb that bolts fast in heat.
The Short Answer
Colorado Frost Dates
Your planting dates depend on which part of Colorado you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Front Range (Denver) | 5a, 5b, 6a | May 1 - May 15 | Sep 25 - Oct 10 |
| Western Slope | 4b, 5a, 5b, 6a | May 10 - Jun 1 | Sep 15 - Oct 5 |
| Mountain Regions | 3a, 3b, 4a, 4b | Jun 1 - Jun 20 | Aug 25 - Sep 15 |
Cilantro Planting Schedule for Colorado
Front Range (Denver) (Zones 5a, 5b, 6a)
Average last frost: May 1 - May 15 · Average first frost: Sep 25 - Oct 10
Western Slope (Zones 4b, 5a, 5b, 6a)
Average last frost: May 10 - Jun 1 · Average first frost: Sep 15 - Oct 5
Mountain Regions (Zones 3a, 3b, 4a, 4b)
Average last frost: Jun 1 - Jun 20 · Average first frost: Aug 25 - Sep 15
Growing Cilantro in Colorado
Cilantro in Colorado's Climate
Your cool climate extends the cilantro season significantly. Direct sow from mid-April — the herb may produce for 6-8 weeks before bolting versus 3-4 weeks in warm zones. Northern Michigan and Minnesota's moderate summer temperatures are genuine cilantro advantages. Fall cilantro from an August sowing is highly productive.
Soil Considerations for Colorado
Alkaline clay soils common along Front Range. Rocky, thin soils in mountains. Amend heavily with compost and sulfur to lower pH.
Colorado Climate & Growing Season
High altitude means intense sun but cool nights. Low humidity. Hail risk in late spring. Short but intense growing season at elevation.
Growing season length varies across Colorado: Front Range (Denver) (5a, 5b, 6a) has a last frost around May 1 - May 15, while Mountain Regions (3a, 3b, 4a, 4b) sees frost end around Jun 1 - Jun 20. This difference matters for cilantro — adjust your planting dates to match your specific region.
Growing Tips
Bolts quickly in heat — succession plant every 3 weeks and grow in partial shade during summer. Let some bolt for coriander seeds.
Companion Planting
Plant cilantro alongside these companions for better growth:
Keep cilantro away from:
The Bottom Line
Last reviewed: March 29, 2026