Is this Japanese Knotweed?

[Spicegirl1234]

Spotted in the garden of a property we’d like to purchase. I fear this is it, chat gpt says it is JK.
Should we walk away?

No I don’t think so

Looks like the lilac runners we get from our neighbour's lilac.

We tried to upload very similar pictures into chat gpt to see if it spotted the differences and it seems to be very accurate, for example has identified the lilac leaves (which I think look super similar to JK). But says this one is JK

JK has leaves in alternative places up the stem- imagine climbing up the leaves like steps. I think this has leaves that are next to each other although the angle of the picture isn’t great. I’ve probably explained that really badly 😂 but Google leaf placement!

Nope that's not Knotweed

I don't think so either. Japanese knotweed has a reddish stem.

I agree. Lilac, not JK.

No I wouldn't say so. If you Google JK the leave are quite different, and reddish stems.

I also think the leaves seem slightly different but I was concerned by chat gpt as I have uploaded this pic and says it’s JK and then uploaded pic of lilac and it did identify the lilac correctly

It’s not knotweed, don’t panic. As others have said, knotweed leaves go up the stems alternatively. There’s lots of it in an area not far from us, so I know what it looks like.

I even ran your picture through PlantNet for you, and it identifies it as lilac. Image attached :)

@Yewtreeberries omg thanks so much! I tried some other websites but all seem to email you the verdict after hours!

I rented a property that had rampant knotweed, it doesn't look like it to me. Very young plants - which will be springing up nearby if it's knotweed - are reddish brown, and at this height it would be a young plant (ours was 8 feet high). The leaves are similar but don't look quite right, the veins on the underside may be reddish sometimes as well (low down on the stem). The stems are hollow like bamboo.

We actually managed to kill 99% of the patch in our garden through regular use of powerful weedkiller applied to the leaves, which is then carried through the root system. It took many, many applications and we had to wait weeks until the whole lot was yellow/black before we finally dug it out. It all came up and we had to dig under the shed to retrieve a football sized chunk of root and a similarly sized ball of what I can only describe as green, thick snot. Weirdest thing I ever saw, but it sort of worked...the creepy little brown bastards still emerged in that corner in the summer, we just mowed them. Only rented there for a year or two.

Leaves are a similar shape but that's not it

@Spicegirl1234 No worries. All of the other suggestions were 1% or less than 1% probability of being correct (versus 81% for common lilac). I scrolled right down the list and Japanese knotweed isn’t even mentioned as a possibility.

Have another image to show the next nearest options after common lilac are only 1%. In my experience it’s actually quite unusual for PlantNet to give quite such a definitive answer!

I remember well the fear of knotweed when looking to buy!

The angle of the pic is bad, one needs to see the stems.

The leaves are 'alternating' and the stems are red and green mottled in the knotweed I have seen.

No, JK has a more pronounced heart shaped leaves, and the leaves are not as smooth and waxy as that,

No, that's not JK, it is subtly different. I have JK growing down the bottom of the garden, its amazing how well it grows!

It has a bad reputation, but has been proved no more damaging to buildings in good repair than any other invasive plant.

I can't eradicate ours as it comes in from the railway embankment, where the victorians planted it to stabilise the banks, as they did widely on the railways, so I just trim it back.

It apparently is delicious, tasting of honey and rhubarb, loaded with vitamins and useful in treating cognitive disorders, but not of course if its been sprayed with weedkiller.

I can spot JK from 100 yards, as I battled it for years growing on the opposite side of a stream that ran across the end of our garden at a previous property. That isn't JK.

Looks like lilac but I haven’t seen JK to compare.

Defo not op

Chat gpt isn't very good at images.