Eastern Gammagrass is one of my favorites! The cows love it also. It starts earlier in the spring and goes later in the fall than most NWSG. It does need to be rotationally grazed or it will be grazed to death. I have not seen mine really spreading much over an area, but the bunch will get larger and larger. I have only been messing with it for 10 years, so I still have quite a bit more to learn about it. It is hard to get established, but once it is going it is very productive. I did learn that it is fairly easy to transplant. I noticed after the cows graze it, there is always a few pieces they uproot and separate from the bunch. If it has some root on it, you can transplant that piece and it will start growing. I imagine you could go out and separate the bunch and transplant larger pieces, but I have not done that yet. Transplanting the pieces the cows pull off is the most dependable way, to me, to get it to spread. Takes some time. The seed is very expensive on a per plant.