You're asking about the clover?  Man, that is so dependant on the weather and seeding date.  In general, if it get planted immediately after wheat harvest (mid July) and we get some rain the clover can get 8-10 inches before going into winter.  If planting gets delayed, things stay hot and dry you might only get an inch or two of growth.  In general clovers are slow to establish and like cooler, wetter temperatures.  I don't think I'd count on them as a summer planted legume cover crop.  I'd consider soybeans, cowpeas or even this sunn hemp I've been hearing about for that purpose.