Green manure

I have some runner bean seeds which I found in the shed (don't like runner beans )  have no idea how long they've been there, plus a load of red kidney beans in the kitchen cupboard (don't like them much either tbh) & I'm wondering if they're actually viable, whether they could be used as a green manure in the same way as field beans?  I don't mind if they can't because I also have fenugreek, mustard & tares or clover, can't remember which now & I suppose I could put them on the compost heap if they're not worth trying to sow.  Any ideas?  I do have access to loads of horse manure but it's moving the stuff, everything is miles away from my allotment & I don't have a trailer so the weight is probably destroying my car so I'm very keen to explore green manures.

dwarf beans are a good green manure and easy to grow

They will all make green manure. Beans do not start fixing nitrogen until they are quite mature so you will be looking on them purely to soak up nutrient from the soil, which prevents them being leached out, and adding organic matter. As green manure rods down it releases the nutrients which are then available for your crops.

Although fenugreek is a nitrogen fixing plant it does not usually do so in our cool climate.

Phacelia is another good green manure plant.