Pennyroyal is an excellent living mulch and insect repellent. Rubbing leaves on on skin can be as effective at repelling mosquitoes as commercial repellents containing DEET without the toxic chemical risk. Use fresh leaves from the plant. Place leaves inside pet bedding to keep it free of fleas.
Pennyroyal is native to Europe, the Middle East and North Africa and is related to mint, with a smell similar to spearmint. Pennyroyal should not be eaten!
It grows in a mat and makes an excellent groundcover that will crowd out any weeds.
Like mint, pennyroyal prefers sun but will tolerate a little shade. Plant it in well-drained soil and keep it moist. It does not like to be dry. Flowering is mid-summer. The lilac flowers grow on stems that are 4- to 6-inches tall.