This native garden in Litchfield is looking good in late summer but it’s not the meadow but what lurks directly behind it, that this post is about. It’s hard to see but behind this native garden is an area that’s heavily maintained with string trimmers for most of the garden season. The reason? Knotweed! The plant that I’m afraid will be the only understory plant that will survive in the Litchfield County landscape within a decade or two.
Why is Knotweed so big, bad and disturbing? Well for one, it spreads by rhizomes like bamboo. Second, it also spreads by seed. It’s currently spreading quickly throughout Litchfield County at a disturbing rate of speed. We’ve been managing Knotweed on this property for years. The strategy we’ve been using is to string trim the Knotweed every 2 weeks, from when the plant breaks dormancy until late summer. In August, we stop string trimming the plant and let it push some leaves. At that point, we switch to herbicide applications. We will then spray the plant 2-3x with a non selective herbicide when water and nutrients are going back to the root system. After many years, with this strategy, we’ve weakened the plant but it not only persists but it still has plenty of energy to spread. Due to the constant string trimming, we don’t allow the plant to flower/set seed and we don’t allow it to gain much strength because we’re constantly cutting the plant to the ground. No leaves means no chlorophyll production which is technically weakening the plant.
If you have this plant on your property or in your neighborhood, I’d highly advise you and your neighbors to start managing it. If not, it will take over. It will take over your native landscape and your ornamental landscape and your property will only be Knotweed in a very short period of time.
