Grit Blogs > Nature and Gardening at the Edge

Pruning one of the world's largest organisms

You probably have read that aspens qualify as the largest organisms on earth because an entire mountainside grove of aspens may be actually one organism appearing as many trees but actually interconnected by their common root system.

Something that successful and pervasion would seem to be a likely pest but people love aspens. They are one of the signature species of the Colorado mountains. Although Colorado doesn’t have the multi-color, multi-species woodlands of the east, people drive to the mountains in the autumn to see the golden and orange hillsides with areas of spruce and pine interspersed. The tree is truly lovely. It is not huge and has a graceful white barked trunk. The name quaking aspen comes from the way the leaves flutter at the slightest breeze. The stems are particularly limber and the tree always seems to be in motion, whether the leaves are green in the summer or golden in autumn. The golden leaves settled onto snow-covered spruce boughs are a beautiful sign in early winter.

But back to not so endearing habits of spreading. Every spring, the female aspens produce catkins similar to willows. The trees produce only female flowers and others only male flowers. Apparently some aspens start from seeds that fall to the ground. However, good many appear to start from the root systems. If you should try digging up an appropriate sized aspen for transplanting, you are likely to find that instead of a root system that somewhat mirrors the top structure in form, two horizontal roots and very few roots going vertically down. One of the horizontal roots, if followed, would lead back to a larger parent tree, and the other horizontal root would lead to more small aspens. These aspens do not transplant well because of the root structure.

The advantage to the root structure is that the homeowner can easily create the aspen grove effect with several trees of various sizes by only planting one or two aspens. The disadvantage is that there will be many small aspens that will grow where they are not wanted. Mowing them off in the lawn usually keeps them in check. If allowed to grow for two or more years, they will need more substantial tools for cutting, as the truck will be woody. About once a year, I clean out flowerbeds and locations too near buildings to keep the aspens from taking over. Since they don’t transplant well, most of these that come from the roots simply have to be killed off. I am not sure how they are propagated for sale in nurseries. Perhaps they sew seed to raise transplantable trees.

So does this lovely tree that can become a pest have other value? I am sure that it provides homes for birds and it is food and dam material for beavers. The wood is very soft and about the only commercial application that I have heard about is toothpick manufacturing. For all the drawbacks that it has, people continue to love and plant the beautiful aspen to have a touch of mountains in their lawn.