When to Plant Eggplant in Colorado
Beautiful purple fruits that love heat even more than tomatoes. Start early indoors for best results.
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 |
Eggplant 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 Eggplant in Colorado
Eggplant in Colorado's Climate
Eggplant is one of the trickiest warm-season crops for cold climates — it demands even more heat than peppers. Asian varieties (Ichiban, Orient Express, 55-58 days) are the only reliable choice. Start indoors 10 weeks before last frost. Black plastic mulch and row cover are both necessary. Container growing on sun-baked pavement sometimes outproduces in-ground planting.
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. Make sure soil has warmed to at least 70°F before planting eggplant outside.
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. Eggplant cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
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 eggplant — transplant timing shifts by several weeks across the state.
Growing Tips
Harvest when skin is glossy and firm. Dull skin means overripe and seedy. Use row covers if nights are cool.
Companion Planting
Plant eggplant alongside these companions for better growth:
Keep eggplant away from:
The Bottom Line
Last reviewed: March 29, 2026