Not "holy" basil, but "hoary basil".  It's an alternative name for lemon basil, also known as Lao basil.  It's used in Thai cuisine, but far less frequently than the other two Thai basils.

Ah thanks, obviously I didn't know that. I've learned something.

Grow it in pots mosha, put the pots in a spot that is sheltered from heavy rain yet catches some sun.  I grew it like that in QLD years ago, herbs like that are ideal for that.
Also, use sandy soil so if it does get wet it drains better.
Lemon grass is another one, it grows fast and will eventually grow out of the pot so you just separate it.

             Good luck with that Micksaraphee. Years ago I had a good Australian mate who lived a few miles from me. He was always asking me to bring seeds to Thailand so he could try to grow them here. He mainly wanted vegies such as green peppers, eggplant and the like. I would go to Bunnings and buy a variety of all sorts for him.
             Every seed he  planted started to grow well and then they would all wither up and die. He wrote to the seed company in Australia (I can't remember the name - Yates???) not expecting a reply but to his surprise they did have the courtesy of replying. They stated that seeds are specifically modified to suit the soils in the area in which they are sold, in this case Perth WA which has sandy soils. They stated that they had researched the area in which he lived (Prachonchai, Buriram) and found that the soils in that area of the Khorat plateau were completely unsuitable for seeds developed for WA. Something to do with ph content and the like.
           They regretted that their seeds were unsuccessful but suggested he purchase seeds locally which no doubt would have been developed for soils in his area.
           You shouldn't have any problem with eucalyptus trees, they grow like weeds around here.