I think the midwest is a sleeper for growing trophy bass... typically we dont have adequate forage or optimum water quality for our bass for 12 months per year. As we get the water quality optimum for 12 months per year and we get the forage figured out for 12 months per year we are going to grow bigger bass than Texas, Florida, and California in private bodies of water.
Bass will grow over the winter months, they just dont typically have much of anything to eat in the typical midwestern body of water during the winter....
Also the fish born in the lake or pond are not the ones that have a chance at growing into trophies.... take the stress out of a bass's life in the first year or two or three and then stock her into the lake or pond that is prepped and ready and you will really start to see unnatural things happening in terms of fish growth.......
