This is an easy question to answer.
…use compost or better yet…worm castings.
The absolute best fertilizer is compost or worm castings. These 2 have much more nutrients, minerals and beneficial microbes than any commercial fertilizer plus they are 100% safe. Commercial fertilizers can kill plants if too much is applied. This cannot happen with compost or worm castings.
Compost can be purchased at most nurseries and home improvement stores or you can make it yourself with a Compost Bin. Worm castings can also be bought locally but online is much easier. Most stores do not carry worm castings. You may be able to find a local worm farm that sells the castings. I was able to find one in my city.
Worm castings are the premium or “Black Gold” of fertilizers. There is nothing better. Plants will grow faster, produce more and turn greener with worm castings fertilizer. You will be amazed.
So what are Worm Castings?
Worm Castings are the end product of a worm’s digestive system. In other words….worm poop. Worms eat organic material and excrete what is not absorbed into their system. The waste is actually more nutrient rich than the stuff the worms eat. It’s amazing.