Am I An Island?

I had a great conversation with a volunteer last week on the topic of exotic, invasive species growing in one’s yard. What sparked the little chat was an observation the garden volunteer made about seeing some purple loosestrife growing in someone’s yard, and “isn’t that awful”? My response was, “well, that depends”. I tend to get an itch when anyone has strong knee jerk reactions to anything on either side of a debate, especially around the topic of invasive species versus natives, as I have expressed in other blog entries. In my not so humble opinion, one needs to keep one’s head and use their their botany/ecology mind when considering such topics.

I had a similar conversation with a former intern of mine while working for Cleveland Botanical Gardens. She pointed to a clump of Arundo donax (giant reed grass), and asked why I was growing an “invasive” species. It was news to me, so I did a little investigating and thinking (i.e. no knee jerking). I discovered Arundo is considered invasive in certain settings and conditions, but what I wanted to know was its means of reproducing/spreading (i.e. seed dispersal). It turns out this species is pretty sterile and spreads almost exclusively via vegetative growth. The conditions under which it was invasive? Wetlands. My plot of land had no contiguous connection to any wetland location and was easily kept in check by my shovel. With no viable seed able to jump ship, my giant reed grass was an island. As a public institution, one could argue I was sending a wrong message, “If they can grow, so can I.” However, I felt the plant’s use as a great hideaway for children in a children’s garden and educational talking point (i.e. this is a grass! Can you believe it? We get reeds for musical instruments from it) outweighed any possible confused messaging.

When making planting and land care decisions, one must use their mind and the best data science can provide, and this is what I shared with this garden volunteer. The key to whether a person’s garden is an island or not, when it comes to invasive plants, is its means of spreading (i.e. seed dispersal, etc). This requires a little digging and thinking. One cannot naively assume their property is so far from the “wild” that they can safely plant, for example, burning bush (Euonymus alata, which spreads via birds eating berries). Birds can travel long distances before they deposit seeds. Your garden is not ultimately an island for most things as we are all interconnected, but in what ways? It is these interdependent relationships a responsible gardener needs to think carefully through.

Josh Steffen, Horticulture and Facilities Manager