Here's a wikipedia link about the plant I'm talking about. I didn't realize it was considered invasive in some parts of the world. So I thought I better add this to our discussion. If you do ever use it, it sounds like cutting back the flowerheads before they set seed would be a good idea! Lantana camera. I see this plant sold in nurseries in the Southwest US, so maybe it's not as bad a this article makes it out to be. Here's to rain for you -- soon!

In another comment thread, @breezin says they are invasive where they are in South Africa. And that they are problems for cattle, goats, and sheep. So maybe Lantana are not the best solution for a drought tolerant garden plant in your area, pretty though they may be. Drought is such a challenge!