The signature spices of Tom Kha Gai, or coconut Thai soup, can readily be grown at home in a themed spice garden. Galangal, kaffir lime, lemon grass, cilantro and bird chillis are the easy-to-grow flavoring agents of the popular soup as well as many other Asian dishes.
In Grow Your Own Spices, Tasha Greer explains how to get started:
Kaffir lime likes semi-dry Mediterranean conditions, similar to bay laurel when grown in the ground. But if it’s container-grown, it needs a deep pot, applications of citrus fertilizer during leafing and fruiting, and consistent watering.
Lemongrass, typically grown from seed for its aboveground, aromatic stalks, likes the same growing conditions as ginger. Just give it full sun for best results.
Galangal is grown from rhizome cutting in conditions just like diner. However, you’ll grow it as a perennial. Allow it to establish in a large pot or deep bed for at least a year before you begin harvesting.
Cilantro and bird chilies are cultivated much like coriander and paprika, needing shade to prevent bolting. Harvest the young leaves and replant for a continuous supply.