Weed growing next to garden shed.

[amateurgardener]

Hi everyone, I would be grateful for your help in identifying this weed. Is this a Japanese Knotweed? Please see picture. Many thanks for your advice!

 

[Chuck]

It isn't Japanese Knotwood. Don't know what it is.

 

[Oliver Buckle]

I don't know what it is, but in that space between shed and fence it is probably getting less light than usual and growing tall and sparse compared to its normal habit. A close up of the leaf may help, is it a three part leaf?
Here is knotweed.

 

[cpp gardener]

Can you get any closer to the stem against the shed? It does resemble a Persicaria/Polygonum, but I don't think Japanese. It looks like it has a wrapping ligule at the node like Polygonum, but a closeup will show more detail to confirm ID.