Turnip and Mustard Problems

Carter wanted to wait to thin the turnips and mustard, but I think we waited too long. Thinning out the mustard now is not that difficult--and I've gathered some to eat already as tightly packed as the plants are, but the turnips are a different story. We bought the seed from the local feed store, so I had to trust Carter, but when I read a turnip seed pack in a store, they are supposed to be thinned to 4 inches apart when the plants are 2 inches high. They are about six inches high now and they're not making turnips. The root tops lie on top of the soil. I'll try and thin them and rake the dirt up on them so that maybe they'll make turnips, but I'm not too hopeful it will work. I think I'll probably pull out one row entirely and plant again (the 3rd time this year) and thin at the right time. I am able to harvest and eat turnip greens now, however, so I'll leave one of the rows just for greens. So far, I like turnip greens better than mustard any way.