Beware the invasive plant:Knotweed

There are at least three kinds of invasive knotweeds – Bohemian, giant, and Japanese knotweed. (latin names: Polygonum x bohemicum, P. cuspidatum, P. sachalinense). All have similar characteristics – they are incredibly invasive and incredibly hard to kill.

This time of year, knotweed is particularly noticeable in the native landscape because it is flowering. I am not sure which type of knotweed this is. The picture was taken on a recent hike on the MA & PA trail in Harford County, Maryland.

Because these plants are so prolific, they crowd out native species. And because they spread by runners, they are hard to contain.

Here is some great information on how to eradicate.

Believe it or not, this plant is still sometimes sold as Fallopia japonica. Growers indicated that this is a hybrid and does not have the invasive qualities that traditional knotweed does. However, a quick review of the garden boards shows that people have problems keep control of the hybrid as well.

I admit, this plant is somewhat attractive, but there is no need to plant it! There are plenty of great, non-invasive alternatives. One idea from the great book Native Alternatives to Invasive Plants is Aruncus dioicus, commonly known as Goatsbeard.

photo credit: Gideon Strauss

For more information on Goatsbeard, check out this site. And here are some more ideas for native alternatives to knotweed.