We tried winter tares last year and vowed never again. They looked a right mess and after we had dug them in they seemed to inhibit any seeds from germinating.
We did a test on beds that were side by side, one had been green manured and one hadn't. We sowed seeds from the same packet in the same way on the different beds and the ones in the green manured beds either took 3 to 4 weeks longer to show or they didn't show at all.
Hope you guys have a better experience!
Cheers
Steve G