The picture quality is poor and I can't see the leaf details I need to see for an ID. Can you post a clearer picture? If your camera has a "macro" setting (sometimes noted with a plant icon), use that setting. A picture of the whole plant might be easier for you to take, just make sure it shows plant details.

But....if I had to guess rather blindly from this picture, I'd say lemon balm. Does it have a lemony scent?

FataMorgana

You're pretty sharp. But I know now that it is lemon balm because I remember that's what I bought. Thanks for jogging my memory.