Overview

Quaking Aspen is one of North America's most widely distributed trees and is iconic to Colorado's high country. Named for its leaves that tremble in the slightest breeze, aspens are known for their smooth white bark with dark knot scars, and their brilliant golden fall color. Aspens typically grow in large clonal colonies connected by a single root system.

Identification

  • Smooth white to greenish-white bark with black markings
  • Nearly round leaves with finely toothed edges
  • Leaves flutter and "quake" in light breezes
  • Brilliant golden-yellow fall color
  • Grows in dense clonal groves
  • Slender trunk with narrow, columnar crown

Growing Conditions

  • Typically grows 40-50 feet tall
  • Fast-growing, 2-3 feet per year when young
  • Prefers cool, moist conditions at higher elevations
  • Best above 7,500 feet elevation
  • Full sun to partial shade
  • Requires consistent moisture
  • Cold hardy (zones 1-6)
  • Spreads by root suckers to form groves

Common Pests & Diseases

Cytospora Canker

Most serious disease, causes branch dieback and black oozing cankers

Aspen Leafminer

Creates serpentine mines in leaves, causing brown blotches

Poplar Borer

Larvae tunnel into trunk, weakening trees

Marssonina Leaf Spot

Causes early defoliation and tree decline

Oystershell Scale

Encrusts branches, weakening trees

Care & Maintenance

Aspens are challenging in lower elevations and urban settings due to heat stress and disease pressure. Provide adequate water, especially during establishment, but avoid overwatering. Avoid wounding the bark which invites disease. Not recommended below 7,500 feet elevation. Do not plant single trees; aspens thrive in clonal groves. Stressed aspens are highly susceptible to numerous pests and diseases.

Why Choose Earth-Wise?

Our ISA Certified Arborists have extensive experience caring for quaking aspens throughout Colorado's mountain communities. We understand the unique challenges these trees face and provide expert care including disease diagnosis, pest management, proper pruning, and health consultations. Whether you need help with an established tree or guidance on planting new ones, our team can help.