Not a clue about this one so I think it will have to be a ''wait and see'' job. At first, it reminded me of Basil because the leaves look so soft, but of course it's not the right shape leaf. There are varieties of this as well as many other possible plants to check in the mint family - of which Basil is a member.
I also had a look at Solidago ''canariensis'' one of the golden rod family, but cannot be sure of this until it gets bigger (if it's going to)