Sure can. If you start feeding them now, they will continue to brood up. If you are using double deeps or want to, the simplest way to get them to draw out the upper deep is actually to not only feed them but break the brood nest up by placing empty frames between frames that have already been drawn out very well. By the time the goldenrod starts blooming you should have the deeps both pulled out and ready for them to store honey in for the winter.