Aspen (Populus tremuloides) commonly are called trembling aspen, quakies or quaking aspen. The fluttering nature of the leaves is caused by the flattened leaf stems, which allow twisting back and forth in the wind.
Aspen are native to the Steamboat area, occurring at elevations roughly between 6,000 and 10,000 feet. They occur in pure stands or mixed with conifers. Often, it is a “nurse crop” protecting spruce and fir seedlings.
Reproduction is by growth of “suckers,” which spring from the root systems of “parent” trees. Although aspen produce seeds on catkins, this reproductive method is said to be evolving out of the species. The root system of aspen groves is thought to be the oldest living biomass of roots. As the trees die out every 100 years or so, the interconnected and interdependent root system lives on and on, repeating the life cycle.
Aspen have many diseases and insect pests. Bark cankers are common. The aspen trees also are affected by borers, insects that insert an egg through the bark that develops into a large grub, which bores about through the woody interior of the tree.
Canker eventually is fatal, unless infected bark is cut away in time. Look for orange blemishes, which can be cut away to healthy cambium and the exposed wound sterilized with alcohol. Borers seldom are fatal. If detected soon enough, coring out the entry hole and injecting pesticide can be done.
Suckers can be dug and transplanted, but only in the dormant season. Since they are dependent on their parent tree for water and nutrients, they die in a very short time if their root stock is severed in the growing season. Deer relish small suckers, so a wire basket is advisable for a while.
Aspen prefer deep, moist soil but seem to do well enough in most local soils.
The Routt County agent or state forester can help with aspen advice, as can the local tree services. CSU’s Extension Service can furnish a plethora of information via the internet or mail.
Omar M. Campbell