Japenese Knotweed or not?

[Blackfingers]

Hello everyone, nice to be here.

I think I have some Japanese Knotweed but am not sure. I have been googling images of it but it's not quite the same as what it in my garden.

The stems are red, a very deep red with no other colour or shading whatsoever. They are not bamboo like (no line around the stem where each leaf stems off), where the leaves appear it's smooth and uninterrupted along the entire length. The stems are more woody, sapling-like and not hollow.

It has not flowered at all.

The leaves are heart shaped and quite large, but are now taking on the weathered and damaged appearance of a dock leaf.

I spotted this plant several months ago and is has not grown much at all since.

It's longest stem is about 4ft.

I would post a pic but it's dark now.

Any clues anyone?

[David E. Ross]

Your description sounds like Persicaria capitata, which is also commonly called a knotweed and used to be classified as Polygonum capitatum. Another common name is pink clover although the leaves are not clover-like at all; this name comes from flowers, which resemble pink versions of white clover.

It does look forlorn as the weather gets cold but does not get truly dormant until the temperature drops below freezing. The plant itself (stems and roots) should be hardy to about 15F. In cold weather (above freezing), the leaves turn red; they will return to green in the spring.

P. capitata can be quite drought tolerant, but it will accept regular watering. It is also tolerant of part-shade although it does best in full sun except in the hotest climates.

My front lawn and my rose bed in back are planted with P. capitata. It forms a dense mat about 2-4 inches thick, so dense that very few weeds will grow in it. I need to trim the edges of where it grows about 2-3 times a year.

[David E. Ross]

[my prior text snipped]

I just saw the links to your photos in another thread. No, that is definitely NOT Persicaria capitata.

Why did you start a discussion about a different plant in the thread about your vines?