Hi theBCnut
Nice list! I have used most of them except for the birch and the bergamot. My research has led me to these observations:
Geranium – Effective as a repellent mostly because of it’s Geraniol content. Ceylon type Citronella has a higher Geraniol content and is MUCH less expensive.
Eucalyptus – Powerful killer of fleas! Contains 1,8-Cineole. Rosemary has similar qualities (1,8-Cineole) and I use it because it has other ingredients that in combination I think make it a more effective flea killer. I also like the smell better! The Morocco type is my favorite.
Peppermint – Powerful flea killer! I don’t like the smell. It is often used in combination with Rosemary for the synergistic effect.
Clove – Powerful flea killer! I stay away from Clove because of it’s phenol content. Phenol’s are in my opinion pretty toxic and can be very irritating.
Cinnamon – Phenol
Tea tree – I don’t like it because of it’s toxicity. Oils that contain Geraniol have the same antiseptic qualities and they are safer and smell better.
Patchouli – Brings me back to the 60’s! Expensive.
Birch – The sweet version contains primarily Methyl salicylate (the wintergreen smell). Methyl salicylate penetrates the skin and I think it is pretty toxic. It is also a powerful flea killer.
The Tar version contains Cadinene which would put it more in to a Cedar type of oil and would also make it much safer.
Cedar – Powerful flea killer and safe to use!
Lemongrass – Repels and kills. Not as effective as Geraniol but it smells good. The citral version of lemongrass smells divine. Safe.
Bergamot – I would only use a Bergaptene Free version because of Bergaptene’s toxicity. It gets it’s flea killing properties from Limonene which is MUCH cheaper in Orange oil.
Spearmint – I love the smell! It contains limonene AND R-(–)Carvone which is also a flea killer and is what gives spearmint it’s characteristic smell. S-(+)-carvone, smells like and comes from caraway seeds
