Fertilizer?

How about fertilizer?

My property has clay and lava rock, not ideal for growing anything that needs nutrients. (I am amazed that coconut and other palms grow in it.)

I had big holes dug and filled with good soil for my maracuyá, carambola, and carissa, but they will need nutrients added. I’m looking for a balanced fertilizer, like a 10-10-10 or 17-17-17.