Pennyroyal in bloom
(Photo courtesy of NetPS Plant Finder)
Plant Height: 6 inches
Flower Height: 12 inches
Spread: 24 inches
Hardiness Zone: 5
Other Names: Squaw Mint, Mosquito Plant
This variety forms a low carpet of gray-green leaves with an intense spearmint fragrance; plant as an understory groundcover; a great base plant for containers; not generally used as a culinary herb
Pennyroyal has masses of beautiful spikes of fragrant lilac purple tubular flowers rising above the foliage from late summer to mid fall, which are most effective when planted in groupings. Its attractive fragrant pointy leaves remain grayish green in color throughout the season. The fruit is not ornamentally significant.
Pennyroyal is an herbaceous perennial with a ground-hugging habit of growth. Its relatively fine texture sets it apart from other garden plants with less refined foliage.
This is a relatively low maintenance plant, and should be cut back in late fall in preparation for winter. It is a good choice for attracting bees and butterflies to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;
Pennyroyal is recommended for the following landscape applications;
- Mass Planting
- Rock/Alpine Gardens
- Border Edging
- General Garden Use
- Container Planting
Planting & Growing
Pennyroyal will grow to be only 6 inches tall at maturity extending to 12 inches tall with the flowers, with a spread of 24 inches. Its foliage tends to remain low and dense right to the ground. It grows at a fast rate, and under ideal conditions can be expected to live for approximately 10 years.
This plant does best in full sun to partial shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This species is not originally from North America. It can be propagated by division.
Pennyroyal is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. Because of its spreading habit of growth, it is ideally suited for use as a 'spiller' in the 'spiller-thriller-filler' container combination; plant it near the edges where it can spill gracefully over the pot. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.