Here's some additional information that I found:
- Lavender needs well drained soil. In fact, if you can add sand or gravel, that will be even better. Poor soil rocks for lavender. I'm very tempted to plant it in some forsaken corner of the yard. Maybe that's what it needs.
- You need a big pot because it spreads (very slowly, but it does) and you need space for the roots.
- I can't find information about making Lavender flower. There was one entry on adding potassium but for most part, nothing. Maybe it really just blooms on its own.
- It's not too fond of watering or fertilizer. It just likes lots of sun.