See above precautions. Some references say Pennyroyal has a light scent slightly reminiscent of roses, although I don t notice it in mine. Interestingly, it is a wonderful companion plant for them, though. Pennyroyal doesn t spread as wildly as others in the mint family, but it is weedy enough to make a good insect-repelling border plant for a vegetable garden. It takes average, dry soil and full sun.
European varieties can take part shade, but prefer a richer soil.
Look for the variety erecta which is more leggy and can be bundled most easily for harvest. The best time to gather Pennyroyal is when the plants are in full bloom, usually in early to mid summer. Cut the stems several inches from the base, and hang in bunches to dry. Rub the leaves off when dry and store them in dark, airtight containers. Like most mints, pinch off the top shoots for bushiness and increased growth.