First off, can you till the soil or is it too rocky??? If you ace till it even a little bit, I would try buying some inexpensive turnip seed. However, if you were going to do turnips, I would do them ASAP as it's getting kind of late for them- but they may still do you some good for this year-especially during late season. What I do is get a 5 gal bucket and fill it with good black dirt and I mix my turnip seed into it and then I mix it by pouring it into a 2nd 5gal bucket about 20times back and forth. Then go to your plot location and cast the dirt (with the seed in it) by hand. Then I take a garden rake and lightly go over the area to ensure I have it good and spread out and even.