If you are looking for an effective all-natural insect repellent, you need look no further than pennyroyal. Not only will you benefit from the insect-repellent properties of this member of the mint family, your pets will, too.
There are actually two types of pennyroyal belonging to two different genera; however, they look very much alike (except when in bloom) with many other similarities. European pennyroyal (Mentha pulegium) and American pennyroyal (Hedeoma pulegioides) are both members, as previously mentioned, of the mint family with the distinctive square stems and lovely fragrance found among mints. European pennyroyal was thought by Pliny the Elder (23 CE – 79 CE) to be an effective flea deterrent. Corolus Linnaeus (Swedish botanist of the 18th century) used the Latin word for “flea” – pulex – when he classified European pennyroyal as Mentha pulegium. American pennyroyal was used by both Native Americans and European settlers to protect themselves from annoying insects.
Pennyroyal is often used to protect pets from fleas. It can be rubbed on a dog or cat to keep fleas and ticks away. You can also used lengths of pennyroyal to weave an all-natural flea collar for your pet. In addition, you can sprinkle dried pennyroyal on your pet’s bedding.
Both Europeans and Native American used pennyroyal in teas and other herbal concoctions for medicinal purposes, such as a treatment for colds and flu or to soothe an upset stomach. It is not recommend, however, that you start brewing pennyroyal tea. The oils in pennyroyal are about 85-92% pulegone, which is a toxic substance. The amount of pennyroyal needed to help you alleviate the condition plaguing you is also the same amount that can poison you. Just use this herb, instead, to repel fleas, ticks, flies, mosquitoes, and chiggers. In fact, pennyroyal is such an effective insect that it is often used in commercial bug sprays and lotions.
European pennyroyal is a perennial and has smaller leaves than its American counterpart. It prefers neutral soil that is rich and moist with a lot of humus added. It can be grown in full sun to partial sun. European pennyroyal can also be easily propagated from cuttings, as well as from root divisions. This variety also tends to be a bit neater in appearance than its sprawling counterpart.
American pennyroyal, on the other hand, prefers an average, dry soil that is acidic. Grow in full sun. This type of pennyroyal is an annual and is usually planted by sowing seeds in the spring. (Seeds sown in the fall will probably not survive the winter.) Seeds should be scattered thickly, since many will probably not germinate. Just cover with a thin layer of soil (up to only ¼-inch). American pennyroyal can also be grown from cuttings and root divisions. (Take cuttings near the end of the season and bring them indoors through the winter so you will have new plants the next spring.)
Both European and American pennyroyal can be invasive. Nevertheless, their mint-y fragrance and insect-repellent properties make them worth adding to your garden.