The best tip for finding a gardener in Hawaii was right under my nose, and I didn't think of it for months. Instead, I just kept paying the guy who wasn't even the gardener I was supposed to be working with. I only know this because I talked to my neighbor, Don, to tell him I was unhappy with the gardener he referred and discovered it's not the same guy who does his garden.
Apparently, the number I called was correct, but another person answered and said he was working for the intended person. He sends over a crew once a month but they always look like they just rolled out of bed. There are no set days or time of month they show up. Although, I have heard from my neighbors that I'm not supposed to let the gardener know when I'm On Island or they'll just come the day before and skip other months. I haven't verified that, but it seems plausible.
See those palms above? You couldn't even see the roots before I trimmed. They've grown at least 10 feet over the past year. Stuff grows so fast here as compared to California. You can read more in my personal blog today and see a bunch of new photographs of my garden at this link: How to Find a Gardener for a Hawaii Garden in Kona.