Sometimes a potted khat bush will look like it needs water when in fact what it needs is the opposite: better drainage. That's the only problem I've (rarely) encountered. Beware of frosts, and native herbivores if you live in the bush. Khat easily withstands drought conditions, but in arid areas where it is grown as a cash crop, khat is notorious for its irrigation requirements. Seedlings may require extra care (mine get a sprinkling of water twice daily) until they're more established.