Many Lavenders available to the general public are sterile hybrids, and the quality of essential oil distilled from these is badly compromised. A period of moist, cold conditioning prior to sowing in a warm place will improve germination. This may be accomplished by mixing the seed in moist potting soil and placing in freezer for 2 weeks, or by sowing the seed in a flat and leaving outdoors in cold weather before bringing into greenhouse to sprout. This is also an ideal herb to start in outdoor nursery beds. Transplant to pots or out to the garden after the slow-growing seedlings produce 4 or 5 leaves.
Lavender prefers a moderate supply of nutrients, lime, and a well-drained soil.
After flowering, cut back to one inch above the old growth. In northerly areas, protect the roots with a deep organic mulch in the autumn. Lavandula latifolia Syn. Native to the mountains of France and Spain. The leaves are spatula-shaped, and the flowering stalks are much branched.