I don't know how you were doing your throw-and-mow, but one thing that drastically improved my germination rate was spreading the seed before mowing. Then mow and spray immediately afterwards (or with 24 hours). Throwing seed on top the duff is a waste of seed. But covering the seed with the duff helps a lot.
That's kind of how I did it. I'd spray, wait a few days for a good rain forecast, then broadcast and immediately mow the dying vegetation over the seed. It seemed promising the very first time. Not as good as tilling but acceptable. From then on it was progressively less effective.
In hindsight I can clearly see the issues I ran into and they make total sense now. Had I considered them beforehand, I probably wouldn't have tried the throw & mow. It was a learning experience.
The issue was mostly leaf litter and lack of width. The widest point of my widest plot is
maybe 40yds. Most of the plots range 10yds-20yds in width. And all are in big mature hardwood forests. As leaves would fall they'd get sifted down into the standing grain. Then when I'd terminate the grain & mow, the leaves and duff would get trapped in the stubble, preventing seed from ever touching dirt. I couldn't mow any lower than about 4" because of unseen uneven ground, rocks, limbs, etc. I did try a landscape rake before mowing but all it did was fill up with debris in about 3ft and then just skip across the top. Tried a leaf blower once but it did nothing. Again, it's all stuff I probably should have thought of beforehand but didn't.
I don't fault the method or blame my failure on it. I truly do believe the method has very real merit. But I also have learned from experience that it's site specific. If I had enough open ground that leaf fall wasn't such an issue I think it could work. If I could burn I'm sure it would work. But I don't think it lends well to long narrow plots in steep hogback ridge country hardwoods.
