Planting trees at high-elevation
When is the best time to plant trees (aspen) at high-elevations (10,000ft)?
Lake County Colorado trees and shrubs
I prefer to plant trees in the spring to mid-summer. The root system is key to tree establishment, and they have a better chance of getting established planting early rather than in the fall. If you do plant in the fall, the trees will require regular watering throughout the fall and winter, which will be problematic at your elevation.