If you want lavender oil that will help you rest, you need to look for these three things: 1. Seek Species: There are many varieties of Lavender and they all have relaxing properties, but the best species for sleep is, hands down, Lavandula angustifolia. 2. Get High: Lavender that was grown 3,000 feet or higher in elevation is higher in linalool, a chemotype that makes you drowsy. 3. Manic for Organic: Organic soil produces higher quality plants with essential oils that do not contain pesticide residue, so look for organic-certified essential oil.