Saturday, August 20, 2011

Garden Villains

A Russian olive is a beautiful and potentially
useful tree. Unfortunately birds are spreading 
this tree's seeds in neighboring yards, fields, 
and wild land areas.

I have some friends that are so busy being wowed by plants in general that they will tell you the virtue of dandelions, amaranth, and plantains.

And I don't have a problem with that. Many weeds are useful and only minor nuisances at worst. But there are many that will do extreme damage to landscapes and nativescapes. 

The weeds that are most annoying to me are trees. This is because most people see a tree and assume that it must be good because it is a tree. They refuse to see that the wrong tree is just as bad as the wrong anything.

The traits that make a tree a weed are the same ones that make any plant a weed:

  • Invasive  The plant is aggressive and moves into new areas easily.
  • Monoculture  A single species dominates an area, allowing for no competition or other niches.
  • Selected Displacement  A plant that totally out-competes a valued (usually native) plant.
  • Dangerous  A species that creates an unreasonable hazard. Remember all trees have some danger.
The weed trees in your area are likely to be different than the ones I am familiar with. You will only find them by researching and asking the right people the right questions.  To start with, you could ask the local urban forester, a park ranger, an ecology professor, or a local conversation group.

As for the right questions, ask if the trees you are interested in meet any of the criteria above. After you ask a few experts you will likely learn more about the tree than you ever thought possible.

Remember good gardening is not just hard work, it is the process of learning and finding better ways of doing things. Especially if you are doing something that is going to be around for a while!