Invasives Dystopia

I've been asked to give the keynote address to a regional gathering of Garden Club of America clubs in October.  The theme that the organizers chose for the gathering is "invasive plants," which gives me a lot of leeway for my talk.  I'm going to focus on introduced ornamentals that have escaped and become invasive pests.

One of the organizers wants to create a poster board of "bad actors," and she wants to include Japanese knotweed (Fallopia japonica) among the plants.  I needed to find images of knotweed for her, and on the way back from the grocery store yesterday I saw a perfect patch just begging for a photograph.  So, I parked and walked over to get some shots.

The area is on the floodplain of a small tributary to my creek just upstream of my preserve.  It is - to put it bluntly - an invasives hell.  An ecological nightmare.  A complete write-off.

The floodplain is an impenetrable thicket of Japanese knotweed.  It's 10-feet tall - the tallest knotweed I've ever seen.  But wait, there's more!  The knotweed is being over-topped by porcelain-berry (Ampelopsis brevipedunculata).  And, just outside the area where the knotweed is so thick, there's a thriving stand of purple loosestrife (Lythra salicaria).  About the only plant I didn't notice was mile-a-minute weed (Persicaria perfoliata), but it certainly could have been there amid the green chaos.

I will admit that bees were enjoying the scene - and not just non-native honeybees, but native bumblebees, too, so I guess the site is not a complete write-off.

Invasive Gulch

Knotweed in flower

Porecelain-berry is rapidly engulfing the trees in the background

The land is owned and managed by the municipal wastewater authority.  Although the site is at the intersection of two fairly significant roads, the wastewater authority doesn't do much to maintain the property.  They probably don't know what to do (repeated herbicide applications would be appropriate), but they do try to mow it down occasionally.  I've tried to talk to them about management, but they're in the wastewater treatment business, not invasive plant control, and I've gotten nowhere with them.

Knotweed (background) and purple loosestrife

Purple loosestrife (mostly) with a little porcelain-berry in the foreground

Of course, since the stream is a tributary to my creek and is upstream of my preserve, all of the propagules produced by these noxious weeds flow downstream and end up you-know-where.

The knotweed in the foreground is being over-topped by porcelain-berry