French lavender likes the dry heat of the Mediterranean, but don't let that discourage you from giving it a try. It's pretty adaptable, provided it has well-draining soil. If you don't harvest most of your lavender for drying, you'll have to prune it back a bit each year to encourage new growth in the present and following seasons. This is best done in the spring -- just because lavender is slightly woody, it shouldn't be treated like a shrub; winter pruning will harm the plant. Lavender is a low-maintenance plant that gives a lot in return and pruning it doesn't take much.
Prune French lavender in the spring once there's a flush of green on the plants and again after flowering.
Grab handfuls of stems and give them a good trim. Andy Van Havelingen of "Fine Gardening" magazine recommends removing about a third of the new growth early in the season. Once that third has regenerated, he then removes another third to encourage new growth at the base of the plant.
Deadhead the spent flowers. If you trim the plants for drying, you aren't likely to do much deadheading.
Prune out old wood only if it is completely dead.