Denver’s first frost in the fall comes on Oct. 3 on average, but that doesn’t mean harvest season ends in September. Soil temperatures are just peaking in October.

The higher the elevation, the more limited the flora. Leadville, which is above 10,000 feet, has just 26 frost-free days in the average year -- not the ideal climate for growing heat-loving tomatoes. However, with care, even Leadville homeowners can grow flowers and vegetables.

Conclusion

All these warnings about water, soil and weather shouldn’t scare away gardeners. O’Connor just suggests being flexible and open-minded.

“Don’t get frustrated, learn from your mistakes, and utilize resources of people that have lived here a long time,” she said.

Source: http://www.networx.com/article/3-rules-of-mile-high-gardening