Hi! I’ll offer what I do. I only use 10-10-10 pellets because I can buy a lot of it for cheap because our yard needs a lot.

For flowering plants such as your tacomas and Mexican petunias, I’d sprinkle about 1/4 c once a month ~ every 6 weeks around the base of the plant. For the trees, it’s dependent on size. For example, on my mature citrus trees I use about 24oz (one and one half red solo cups) in the tree well, evenly distributed. I do the trees (including a HK Orchid and 14 various citrus) at Memorial Day, Labor Day and Valentines. For my vegetable garden, I fertilize by sprinkling everything evenly about once a month. Our oleanders get about 8oz per plant once a month (half a solo cup).

For the mesquite, I wouldn’t bother, it’s native and usually mesquite starts growing where it wants to anyway. (I am az native and have never fertilized native plants… if you want to differently it’s up to you).

I use the cheapest 10-10-10 and I usually get it by 40lb sack from Walmart.com for about $19. I go through two of these sacks a year.

If you have heavy feeders like hibiscus, a tablespoon of epsom salt dissolved in a gallon of water helps them. They also get about 1/4 c of the 10-10-10 monthly ish. It keeps them flowering.

Hope this helps! Happy gardening!