Pennyroyal Mint

Start pennyroyal seeds indoors 6-8 weeks before your last spring frost. Sow seeds on the surface of moist seed-starting mix in warm conditions around 70°F and provide light for germination. Seedlings typically emerge within 2-3 weeks and can be transplanted once they develop their first true leaves.

Harden off seedlings by gradually exposing them to outdoor conditions over 7-10 days before transplanting. Move them into the garden after the last frost date when soil has warmed, spacing plants 24 inches apart. Water well after transplanting and keep soil consistently moist for the first 2-3 weeks to establish a strong root system.

Direct sow pennyroyal seeds outdoors after the last frost date has passed and soil has warmed to at least 60°F. Scatter seeds on the surface of prepared garden soil or containers, press them gently into contact with the soil, and keep moist until seedlings emerge.

Begin harvesting pennyroyal once plants are well established, ideally after 90 days from seed. Pinch off individual leaves or stems as needed for fresh use, harvesting in the morning after dew dries for the strongest aroma. For larger harvests, cut stems back by about one-third, which encourages bushier regrowth and prevents the plant from flowering excessively.

Pinch back young plants when they reach 4-6 inches tall to encourage bushier, more compact growth. As the plant matures, regular harvesting or light pruning keeps it from becoming leggy and promotes more prolific foliage production. In spring, cut back winter-damaged growth to stimulate fresh, vigorous growth from the base.