Lavender (scientific name Lavandula) is a family of fragrant shrubs native to Madeira, the Mediterranean and the Canary Islands. All members of the genus produce profuse displays of purple or lavender flowers on tall, spiky stems. French lavender is a variety with gray, serrated leaves. This tender plant is only able to survive the winter in Sunset's climate zones 8, 9, 12 through 24, 30, 32 through 34, and 39.
Choose a location for your lavender garden that gets full sun, where the soil drains well.
Spade the soil up well and mix in compost until the soil is light and will drain easily.
Pull up and discard any weeds. Young lavender plants grow slowly and can't compete with faster-growing weeds. It's critical to start out with a clean flower bed and to pull weeds as the lavender grows.
Space your established lavender plants according to the effect you desire. For maximum visual impact, plant your lavender 2 to 3 feet apart, so each plant can grow out fully. If you want a hedge-like look, plant the lavender close together, so they will intermingle as they mature.
Set each plant into the soil so that the top of the root ball is just below the surface, and fill in around it with more soil. Add a good layer of mulch to the lavender bed, but leave a circle of space about 2 inches wide around the base of each plant.
Water the plants well. As they grow, only water them when the soil has completely dried out; then, water them thoroughly.
Prune your lavender plants in the spring or late fall after you've harvested the flowers. Cut about a third off the tops of the plants.