Backyard plant ID needed please

This plant popped up next to my plum tree this spring. At least I just noticed it this spring :p. I was just about to get rid of it. But decided to check what it is first. Thanks for the help. Has not produced any flowers.

 

Looks like a Buddleia.

 

Recently designated a noxious weed up here.

 

hmm using that hint and google. Is it knot weed?

 

Butterfly bush, as already indicated.

 

Yup, definitely Buddleja davidii. Excellent for attracting Butterflies but sadly classed as a serious weed in quite a few countries. They are now talking of making it a pest species, right up there with Japanese Knot Weed, here in the UK. There are quite a few ornamental varieties of this shrub and several dwarf ones on the market but chances are, if this has self seeded, it'll be the species. Probably worth taking it out before it takes over the garden. They're pretty vigorous!

 

thanks for the help everyone. Got confused on the initial ID since mine hasn't flowered.