Our local retail nurseries reflect the prevailing purchasing attitudes in the US—basically we want it all! We don’t just want our native rhododendrons, ferns and columbines…we want to jazz up our gardens with unique, showy species from every corner of the globe. And with a global economy like we’ve never seen before, it’s no problem to have just that. Or is it? It turns out that yes, indeed, it is a very big problem because this historically quick dispersal of non-native species is, in fact, causing an immense strain on our native habitats.
“Exotics” refers to a plant or animal that people have moved to a place where it didn’t previously occur and where it hasn’t dispersed by natural means. There are now approximately 5,000 exotic plant species that have escaped from cultivation; meaning that they have escaped out of the bounds of a controlled area and out into the surrounding environment. Approximately 1,500 of those plant species are considered invasive. Once free, these invasive plants can wreak havoc on ecosystems as the natural controls in their native environments, such as parasites and predators, don’t exist in the new habitat. Without these limiting factors to keep them in check, they out compete native species for resources including water, nutrients, sunlight, soil and literally space. Eventually they take over and form dense, single species areas that force out native vegetation and cause an extreme imbalance in the entire ecosystem. Scotch broom, English Ivy, and Purple Loosestrife are well known invasive plants in our area, but there are literally hundreds more. Extensive lists can be viewed by clicking on the resources at the end of this article.
So what to do? For starters, we all need to be more conscious of the plants we are purchasing and using in our yards and gardens. Native species are always the safest bet, but it only takes a little digging to find out where that plant you’re purchasing originated from and how it can affect your local environment. Again, for more information (including what is being done to combat invasive species and how you can help), please see the links below. Happy and safe planting everyone!