Care for a lavender plant by planting it in rich, well-drained soil, placing it in a sunny location, watering the soil when it has almost dried out, and pruning it every spring. You need to mulch the plant regularly and fertilize it only if the soil becomes too poor.
Use well-drained soil that has a neutral pH when planting lavender. Damp or clay soils cause root rot, so you need to lighten them with organic matter first. Add gravel around the base of the plant to help improve drainage. Choose a location for the plant that has plenty of full, direct sunlight. Lavender requires very little water. Give it moisture only when the soil almost dries out. However, if it dries out completely, flowers don't form.
Every early spring or late winter, clip off any damaged or dead limbs, and spread a thick layer of compost around the base of the plant. Before buds begin to form, add the gravel mulch. After the lavender plant flowers, prune back the plants. During the fall in cold climates, mulch the plant with evergreen boughs to protect the roots from the cold. In humid climates, watch for fungal infestations, and treat any problems immediately. Harvest lavender as the flowers start to open, and dry them out for later use in the sun over several days.