I only tried Lavender once in the mid 1970's but it succumbed during a rainy, humid summer. There was an article in our Daytona Beach newspaper some years ago that stated the best Lavender species for Florida's zone 9 were Spanish Lavender (Lavandula stoechas) and Lavender (Lavandula x intermedia 'Grosso') They just have to be protected from too much moisture and shouldn't be mulched.
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!