Answer: My personal philosophy is that I want to build up my soil so it can support plant growth. I resort to "plant food" only when, for some reason, my soil isn't able to provide the necessary nutrients. So I would suggest you focus on the soil rather than the fertilizer.
If you haven't already done so, you may want to have your soil tested. This is a good way to determine what, if any, fertilizers are needed. There's no point in fertilizing when you don't have to, and it can be dangerous in that excess soluble fertilizers can leach away. This is one source for water pollution.
I add compost to my beds every year. I use it to mulch all my perennials, and add it to every planting hole. Compost is a wonder soil additive--it increases water-holding capacity, improves drainage, and provides some nutrients in forms that won't leach away. I also add other organic matter whenever possible--I mulch with grass clippings, cover my garden with fall leaves which I till under in the spring, and add composted manure when I can. All these contribute to the soil's health, and ability to support plant life.
I sometimes use a soluble synthetic fertilizer (the kind you mix with water) in the spring, to give my plants a little boost. Always follow label directions carefully, because too much can harm plant roots. I also use kelp/fish emulsion liquid fertilizers.
When choosing fertilizers, read the label. It should give you instructions on when and how to use it. I'd probably stick an occasional feeding with water-soluble fertilizer for your annuals. An annual application of a compost mulch may be enough for trees and shrubs, depending on your soil health. If you choose to use a fertilizer, a slow-acting one like Osmacote should be fine. If you follow label directions, you shouldn't need to "double up" on fertilizers on the same plant.
When using bone meal or dried blood, be sure to wear a dust mask to avoid inhaling the particles. If you'd rather not use the materials, there are other options for applying the same nutrients.
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