Corn will not pollinate correctly if it is not in a rather dense clump. If you grow it in your garden you should plant 3 or more rows(or a square/circle). Otherwise you will get mostly empty cobs.
3 rows is not nearly enough. I grow corn, and even with 9 rows, 20' each (roughly a 20'x20' square, with nearly 200 plants), I still hand polinate (takes about 5-10 minutes every 2-3 days once you start seeing silk). I doubt that most home growers will get anywhere close to enough density for good wind pollination, but hand pollination is not that hard.