In Captain Cook, Kona, Hawaii there is the rather unique Greenwell Ethnobotanical Garden that features both native plants and trees and those introduced by the Polynesians. It takes some walking to see it, but imo it is worth the effort.

Try akaka falls in hilo..very lush and plants galore!
or go visit some nurseries
or panaeva zoo!plants and animals!
or Kona outdoor circle gardens
enjoy!
Bud

See, all the more reason for the Islanders to get their gardens on that garden museum - it could be a one stop shopping for places to see.

I'm going to get over to the Islands at least once in my lifetime.