Japanese Knotweed has a terrible and well-deserved reputation as an aggressive thug. This semi-woody perennial is native to eastern Asia, but was introduced to North America in the 1800s as an ornamental and was also used for erosion control. It has now become established across much of Canada and the United States. It spreads rapidly and is very hard to discourage. A neighbour planted Knotweed in a rough area in her garden but it quickly expanded into other areas and she has spent years trying to get rid of it.
Given this reputation, I was hesitant about adding a variegated form of knotweed to my garden, but I had read that the variegated form is much less virulent and decided to give it a try.
Japanese Knotweed is sometimes referred to as ‘bamboo’ owing to its growth in dense clumps of round, hollow stems. It also has an assortment of scientific names. This genus of buckwheat is commonly referred to as Polygonum cuspidatum, but also Fallopia japonica or even Persicaria japonica. I purchased my variegated plant as Fallopia japonica ‘Variegata’. Planted last spring, to date it has been very well-behaved.
Growing in nearly full shade, Variegata adds an interesting element to a section of the garden that can be a little dull, especially before neighbouring geranium ‘Rozanne’ is in bloom. Variegata receives a bit of sun in the morning, and in this light, Variegata positively glows, taking on an ethereal presence.
A bonus is the way the spring shoots emerge from the cold ground. The colour of the new leaves is a remarkable rosy peach shade. The first two photos were taken on May 13th and May 19th. Now, nearing the middle of June, Variegata has reached its full height of about 4 feet, with gracefully arching stems.