Agree, if you get them into the ground this weekend, that will make them take off. Be sure to put some granular fertilizer around them, as broccoli plants are heavy feeders. Then shade them for a couple of days after transplanting, and gradually remove the shade. Water deeply every day. You'll have broccoli to eat before it gets too hot. This is my favorite timed-release fert for leafy things. Available at Lowe's or off amazon as brand name "Nutricote" - same stuff, different name.