Basil does act like a weed when the weather starts to warm up. It "bolts" really fast so you have to stay on top of picking all the flower blossoms as quickly as you can. As Burnt said, you want it to be bushy if you can manage that.

Maybe I read this the wrong way. Is it just that you have too much basil, or is the basil getting "weedy"? If the latter is the case, pinch it WAY back, and keep pinching to encourage it to grow more bushy and less weedy. If mine starts to flower - I just cut it in half. If it flowers, it will bolt and die.

And may I add how envious I am. In Montana, we've just escaped from days of hammering rain in the lowlands and snow in the surrounding mountains. Even the weeds aren't growing like weeds yet.

Pesto! Freeze it in ice cube trays (I keep some designated only for things other than ice, which I still make the old fashioned way), pop them into ziplocks, and you're ready for the many things you can do with it. Such as make an interesting aioli for the current contest.