Japanese Knotweed Jumped the Wall

Did you know that Japanese knotweed jumped the wall?

During the eighteenth and nineteenth centuries English gardeners hosted exotics.

They took great satisfaction in growing plants that flooded the country from Asia, Africa, and the Americas.

Plant hunters then searched the globe for worthwhile garden plants.

There were various kinds of plants, including vines. One such entry was Japanese knotweed.

Unfortunately, Japanese knotweed became an unwanted invasive species.

Garden historian Stephen Harris writes about this vine in his book Planting Paradise: Cultivating the Garden 1500-1900.

Harris says, “Once an exotic plant has ‘jumped the wall’ it can have profound effects and often very difficult to control.”

The example he cites is Japanese knotweed. [below]

Harris says, “Japanese knotweed [is] a species which has now spread over much of the UK following the flurry of interest it aroused in the mid-nineteenth century.”

It is listed by the World Conservation Union as one of the world’s worst invasive species.

Botanical gardens, like Boston’s Arnold Arboretum, still search the world, especially China, for plants that will grow in US gardens.

Today we know a lot more about invasive plants than we did when Japanese knotweed first arrived in England in 1850.