Pennyroyal is a pungent mint that spreads rapidly along the ground. It has a lower growth habit than other mints which makes it an interesting ground cover. When it starts to grow tall, a quick mow is a good way to keep it in check and lower to the ground. This happens maybe twice a year depending on your preferences.
Not quite as invasive as other mints, Pennyroyal still should not be planted where it can interfere with other plantings.
Pennyroyal is not a culinary herb and should not be used for tea or cooking.