This perennial mint relative bears whorls of fluffy lavender-purple blooms in late summer and fall. It is native to parts of Europe and Asia but has become naturalized throughout much of North America. It often is found growing along waterways, a nod to its preference for moist soil. Like other mints, pennyroyal can spread aggressively, so keep it contained. Pennyroyal has been used as an herb for hundreds of years and is sometimes called fleabane due to its insect-repellent nature.
Light: Part sun, Sun
Height: 6 to 12 inches
Width: 3-6 feet wide
Flower color: Blue, Purple
Seasonal features: Fall bloom, Summer bloom
Special features: Cut flowers, Fragrance, Good for containers
How to Grow Pennyroyal Herb
Pennyroyal can be propagated from seed, cuttings or spring division. The seed needs light to germinate but grows quickly once it sprouts. Plant them in prepared seed beds outside after all danger of frost. Sow the seed on the surface of the soil and mist the bed to moisten it. Keep it moist and germination should occur in two weeks. Divide established plants every three years in early spring for the best form and production.
Pennyroyal is an easy to grow herb. European pennyroyal makes a wonderful trailing plant when grown in a hanging basket or at the edges of mixed color containers. American pennyroyal can be grown indoors in troughs or outside in the kitchen garden.
Pinch the terminal ends of the herb to stimulate bushiness and a more compact growing shape. Grow pennyroyal as a ground cover in sunny areas with junky soil. The plant will persist even in unfavorable conditions and can be helpful in vegetation-free zones as an erosion control.