Any complete fertilizer will do. I like to use a fertilizer with micros. Usually for most plants you feed them after they flower and just before they have a growth spurt.
You need to scratch the fertilizer into the soil if it is granular or you can use a liquid food. For the long term it is also good to add some compost around the shrubs, but do not tough the trunks. Compost can be used like mulch, it will help feed the soil and the soil organisms will come up and pull it down. You should replenish the compost as needed.
Happy gardening in Hawaii. Gardens are where people grow.