The essential oils of a few plants have shown repellency against insects. Keep in mind that protection is often short-lasting (usually less than 2 hours) and does not demonstrate as effective protection as DEET.  According to the PennState Extension, the following essential oils have been shown to repel insects:  • Allspice • Basil • Cajeput • Cedar • Cinnamon • Citronella • Garlic • Geranium • Lavender • Pennyroyal • Peppermint • Pine • Rosemary • Thyme • Verbenaz