Vegetable Gardening in Hawaii
In the last 15 years of off and on growing of vegetable gardens in Makawao and Nanakuli, I have discovered some vegetables are easy to grow and productive, and others aren't. Vegetables planted in the ground are susceptible to root-knot nematodes. Before I discovered how damaging these are I watched cucumbers, peppers, string beans, eggplant, strawberries, and tomatoes get up to bear only to die back and whither. These I have found must be grown in pots of sterile soil. sweet potatoes, green onions, taro, okra, dry-land watercress seem to do well in ground. They must be resistant to the nematode. Keep in mind, the pineapple growers fumigate with a very poisonous chemical to rid their fields of nematodes, and that chemical has poisoned the ground water on all the islands. So getting rid of the nematodes in the soil is difficult if not impossible. Squash, beans, and cucumbers all get rust. You make the rust worse by overhead watering. Some people spray with dormant oil and fungicide. I have heard baking soda is a good fungicide with dormant oil, and it is cheap and non-toxic if it works.
I hope other gardeners who read this post will offer their advice. We gardeners need experienced growers to save us from trial and error.