By Greenfingers
Dorset,
United Kingdom 
Can anyone ID this for me please? I noticed it growing by my shed door last year, I didn’t plant anything there. I think it had yellowy/orangy coloured flowers. It’s huge already this year but I’ve no idea what it is....
17 May, 2018
Answers
I suspect Geum urbanum is its true identity. a small 5-10mm yellow flower. dig it out as it will rapidly spread and set seed.
18 May, 2018
Thank you both for your suggestions.
Jimmytheone, I’ve googled both of yours but I don’t think it’s either, unfortunately.
Seaburnbirl, I think you may be right, I’m going to let it flower to get a positive ID before getting it out if it’s a thug.
18 May, 2018
Agree with Seaburngirl. Pops up all over the place here.
19 May, 2018
Looks like Astilbe or Meadowsweet (Filipendula ulmaria).
18 May, 2018