Anybody positively identify this as Knotweed?

moneyistooshorttomention

Hoof_Hearted wrote: »

I'll get a close-up of the leaf tomorrow. It looks as though it is in a small area and not near the house. No idea how it got there, if that is what it is.

Yep....close-ups of both a larger leaf and a small young one (ie for that furled-up thing they do to start with) and then we should be 100% certain.

One of a stem would be a good idea too if possible.

moneyistooshorttomention

ManuelG wrote: »

The OP now has me snapping photos of all kinds of red stemmed plants while going for a walk People giving me odd looks outside Lidl and the bus stop when I stop to take photos.

Think I need a plant forum!

Their stems (at least the ones I've seen) are sorta a bit like rhubarb stalks in appearance - a bit mottled type red - rather than solid red iyswim.

Which is not entirely surprising because its possible to eat JK shoots and stems and the stems can be used as a rhubarb substitute. Mind you - I've never actually done that myself - because I've always been so aware of having to be very careful in how I foraged it, in order not to drop any.

I'm drawing a bit of a blank on foraging it myself - as, in my last area, I was on the lookout for it and never spotted any. In this area - I spot it alright and loads of it:mad: - but I'm too wary of whether weedkiller might have been applied on it - because every time I spot any anywhere near me I promptly tell the World where it is/my opinion of the culprit:p

Ivana_Tinkle

OP, I'm fairly sure that's bindweed, not knotweed. The stems of knotweed are dead straight - more like bamboo - and thicker than in your photo. Also, knotweed leaves are slightly less of a pronounced heart shape. The whole plant is less "wispy"-looking. Certainly, if the plant in your picture is some kind of knotweed, it's not the same kind I've been dealing with for the last three years, and I wasn't aware of there being more than one type.

Davesnave

Ivana_Tinkle wrote: »

OP, I'm fairly sure that's bindweed, not knotweed. The stems of knotweed are dead straight - more like bamboo - and thicker than in your photo.

Having enlarged the original photo, I'm inclined to agree that it doesn't look like typical knotweed, especially the horizontal stems, but bindweed normally exhibits twisting growth, so it's not a great match with that either.

There are other plants which look similar: houttuynia cordata in non-variegated form being one of them.

This is getting to be quite a puzzle!

Hoof_Hearted

Ivana, it definitely isn't bindweed. I'm very familiar with bindweed which, as far as I'm aware, is a climber and doesn't have red stems.

charlamine

This looks exactly like what we have growing behind our garden, which is bindweed, it invades everything it can climb in the spring and summer and we keep it cut back, but it is literally taken over my neighbours garden, then in the winter it dies off, not to be seen again to the following spring.

If it is JK then the surveyor who came to our house for buyer completely missed it!

daveyjp

My 10+ years of experience says that is 100% knotweed.

They are first season new growth shoots from a rhizome of a larger plant which may will be the other side of that fence, probably about 1m away. The existing plant will be 1-1.5m high by now. By the end of September that plant will be of a similar size.

If there is no other growth nearby this growth is from contaimnated soil, or introduction from another source.

Leave it for now, glyphosate in about a month and two weekly until the end of September. If there is a larger infestation nearby it needs a professional to spray and eradicate, but don't get ripped off.

Eejay

Davesnave wrote: »

Having enlarged the original photo, I'm inclined to agree that it doesn't look like typical knotweed, especially the horizontal stems, but bindweed normally exhibits twisting growth, so it's not a great match with that either.

There are other plants which look similar: houttuynia cordata in non-variegated form being one of them.

This is getting to be quite a puzzle!

Yes I've been looking for ages and that was the only plant I could come up with too.

The new leaves curl out from the top rather than underneath, the vein pattern is different, the leaves look heart shaped rather than flat and they seem to be about as wide as they are long, whereas the JK is slightly longer than it is wide. It might still be JK but why does it not look the same as all the pics I can find? Are there other varieties?

Could it be from the root of a tree or are there no trees around? I have some similar leaves growing out of a tree stump in the garden (totally different stems and pattern) and it's just the tree regrowing, so wondered if it could be something like that.

moneyistooshorttomention

charlamine wrote: »

This looks exactly like what we have growing behind our garden, which is bindweed, it invades everything it can climb in the spring and summer and we keep it cut back, but it is literally taken over my neighbours garden, then in the winter it dies off, not to be seen again to the following spring.

If it is JK then the surveyor who came to our house for buyer completely missed it!

Two of my friends in this area are also recent incomers like myself. Neither surveyor told them they had JK - but both of them have found it in their gardens since.

I would think Davesnave is probably correct in saying that its pretty young JK - rather than a very long-established patch - and that is what is confusing some people.

I understand its a good deal easier to deal with if nipped in the bud very promptly. Its obviously had a bit of time to "get going" - since its in 2?/3? gardens that are next to each other. Best not to give it a chance to get any more foothold.

As for how it got there in the first place - maybe next door neighbour accepted a plant he was given by a friend or something and that plant brought "passenger" with it? I suspect that's how it got into one of the nearby locations to me that I know of.

Anyway, we should all be able to certain one way or another when OP comes back with those close-up photos.

Riggyman

That's definitely baby Japenese Knotweed. Buy some glycophosphate based weed killer from Amazon (or roundup from your local garden centre, the stuff that says "kills Japenese knotweed" on it). Apply liberally. These plants will go black and die within 1-2 weeks. Keep an eye on the area and spray anything else that appears, probably, but hopefully not, next spring.

No need to panic. Keep applying glycophosphate and it will go.