Variegated Japanese knotweed

(Question)

Is my Fallopia japonica ‘Variegata” invasive as it is part of the Japanese Knotweed family?  I have had one plant for 10 years which has two shoots and has spread about a foot.  After hearing a great deal on the radio about the invasive nature of the Japanese Knotweed, I thought I should check things out before planting the Fallopia japonica ‘Variegate” which I’ve just purchased.

(Answer)

Japanese Knotweed can indeed be a very aggressive, fast growing, invasive plant and has been in the media recently for its ability to escape into ravines, culverts, marshes, river banks, wastelands & roadsides.  It is primarily spread from rhizome growth or root fragments being transported from one area to another, rarely will a colony establish from seed.  Planting a nursery specimen surrounded by a deep impermeable border or in a pot may be a safer alternative to planting it straight into the garden soil.

If your garden abuts a natural environment or protected habitat, an abundance of caution should be used as escaped plants can endanger or destroy that natural ecosystem.

Below find links to the Oregon State University website and the Ontario Ministry of Agriculture, Food & Rural Affairs website, for further information on the plant and how to contain it.

https://www.omafra.gov.on.ca/english/crops/facts/ontweeds/japanese_knotweed.htm

https://extension.oregonstate.edu/gardening/node/965