experimenting with sweet potato grown in the same patch as pumpkins,i figure i will pick all my pumpkins then dig my sweet potato,they are looking good,every body says they need to grow on a hill,and they dont like any fert,so i planted a few on a hill,i put 0-0-60 on one roll,18-46-0 on one roll,put nitrate on one roll,cow manure on one roll,what roll do you think will grow the best,