A big suprise

a weed is a plant in the wrong place.if you dont vissit much then it mite be in the right place.it looks like a typical baught plant seld seeded and quite nice.maybe weight till it rflowers then decide

It is a Delphinium you are lucky.

Certainly looks like a delphinium

Looks like delphinium (or possibly Aconitum) to me too Bernhard. I wish weeds like that would turn up in my garden!,

Thanks to Inverglen, Jess and Wyeboy for the Delphinium identification. I am delighted, but what on earth is it doing flowering in October? If Aconitum is also a possibility, how will I be able to tell for sure. Should I wait til next year and see how it behaves once it is established? I wonder if a seed was dropped by a bird as recently as August and it germinated and is desperately trying to make up for lost time.

I have Delphiniums in bud at the moment, but they are on plants which flowered earlier and were cut hard back to encourage another flush of flowers. I won't get any more after these flowers die.... So the answer is - leave it to flower and then cut off the flower stem to the ground and let it die back naturally. When the spring comes, you will need slug/snail protection as the new shoots of Delphiniums are s/s magnets! It isn't an Aconite, I'm sure. Your bird friend brought you a lovely present!

You sooooo lucky to get this delphinium grow as a weed. Just look after it and you may get more. Mine always die off botritus mildew or flyattack... so well done you.!

The common name for aconitum is monkshood. If you saw a flower you'd understand why - they look like a monk's cowl. Delphinium flowers are almost flat, held in a vertical plane. So it will be easy to tell them apart, but I go with the majority and think you have a delphinium on your hands.
PS. Aconitums are poisonous

It is definitely a delphinium, no slug attack, you are lucky!! , wish I had a garden with bits I don't visit very often!! Janet

very nice picture

I'm a bit confused about the close-up picture I posted on 3rd October under the question 'a big surprise' because none of the Delphinium pictures I can find look like this one. I don't want to sound like a doubting thomas but are you all sure mine is a Delphinium and if so could anyone identify the variety? I hope I'm not trying your patience too much.
Regards
Bernard