I like the slow release kind but I mix it into the soil when it's being tilled before planting. After that, I don't feed mine again in all honesty. Just be aware that you can feed them too much and do more damage than good so it's important to follow the directions on the box no matter what kind it is. Only thing I do is use 7-Dust to kill the bugs and beasties apart from a bit of hoeing, trimming and weeding.