Hi Patti,
The main ones I grow are Provence and stoechas. The fringed lavender does well also.I usually just treat my plants as short lived, and try to get new plants going every year..I also have "Goodwin Creek Gardens, with a wooly leaf that does fairly well. The main issue, around here, is we have a lot of rainfall, and high humidity. I try to plant them in the fastest draining soil I have..My best plants are in a very sandy soil, and I never directly water them.. there are enough adjacent plants getting watered, that they never need additional.I also like to plant them with the soil mounded up slightly.I've had lavender (english) persist for a few years, my oldest plant was 4 yrs old, when it finally gave up. I think it depends a lot on the year, and the way they are planted (and watered) So it IS possible to have lavender on Kauai! Just has to be babied a little.Of course, it will never be as luxurious and pumping flowers, as it did for me in Sw Oregon! I had a long sweeping driveway, planted with all different lavenders, that was truly awesome!! Email me if you have any questions.
Aloha, Christine

There ia a lavender that my friend from France called a "French" lavender growing in a windy dry spot of our yard. We are in a fairly wet location, the Hamakua coast, and I didn't think lavender would grow. So far it has survived the wind and neglect - not to mention the chickens - for two years. It has flowered twice, too, so I continue to ignore it and it continues to get bigger.