Fertilizer/Soil and pH: Supplemental feeding is not necessary as Lavender prefers a lean soil, although plants appreciate an occasional side dressing of compost. Perfect drainage is a must, especially through the winter; plants will die in wet soils. A pH close to or slightly above neutral is best, so add lime if your soil has a pH below 7.0. A gravel mulch is beneficial and helps to keep the crowns of the plants away from excess moisture.