If you're dreaming of an aspen forest in your back yard that will provide decades of bright yellow fall foliage, you'll be out of luck.
Though thousands of aspen are planted in urban landscapes, few will live longer than 20 years and only rarely will they turn a brilliant gold in the fall, as they do in the mountains.
Aspen need an acid, light soil, made up of humus, which is created in part by decaying leaves and other debris of the forest. The heavy, alkaline clays, prevalent throughout the Front Range, just won't cut it.
Aspen roots also need special fungi, called mycorrhiza, growing on their roots. Mycorrhiza help plants take in water and minerals from the soil, but these fungi don't survive oxygen-poor clay soils.
Finally, aspen trees propagate by "suckering" -- sending up sprouts from roots. When these sprouts appear in our urban landscapes, they spread into lawns and often are mowed off leaving wounds for diseases to enter.
While aspen truly are amazing trees, they achieve their greatest glory growing for 50 or 60 years in the foothills and on mountain slopes, just as Mother Nature intended in the first place.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010