I have recommended soil tests to clients only 4 times and this was one of them. (The fourth one was on the very same day!) If you are taking care of your soil, you should not need much or any fertilizer. Most clients I meet with are not taking care of their soil though, and for this I usually suggest compost and other organic matter. These are slow-release fertilizers. In both cases, compost or high quality top soil had been added to various areas and plants were still not thriving or even dying