You can plant soybeans as late as you want within reason. The young green plants are a deer magnet. Most will not produce grain and as soon as a decent frost hits they are worthless. The only way you will get grain is if you plant a real quick maturing variety. Some farmers here can harvest their wheat and plant beans right away and still get some grain produced, but they are special beans specifically for that purpose. I also don't see how this would help with a small plot either. If you have the only green soybeans in your square mile while all the others are yellow or brown the deer will find them and quickly destroy them if you have decent deer numbers. The ONLY way I am able to plant small plots of under an acre without protection is because I have low deer numbers AND I am surrounded by other bean fields - so I take a few deer and really spread them out.
I once had an area of my bean plot that had decent weeds so I sprayed and dicsed and the beans that grew shattered and grew. The deer loved them. But like I said they didn't last long because what the deer didn't eat the first decent frost killed. So you are going to have to consider when that first frost hits in your area and how that fits into how you hunt. Beans like this are similar to planting AWP - they are a deer candy and don;t last long, however the AWP will tolerate the frost while the beans won't......neither handle browse pressure (AWP and ag beans). You may even be better off with AWP - or at least consider it. I also know forage beans like Eagles and the like will stay green longer than ag beans tend to, but they still will die with the frost.
