First of all, you need to decide an appropriate place in your home for growing the Pennyroyal. Lawn or yard is the best place where you can grow it.
You should take the Pennyroyal seeds and sow them in the soil of your yard or lawn at home. Make sure you sow the seeds of Pennyroyal in spring or in late fall season because both of these seasons are suitable for growing Pennyroyal.
You need to sow Pennyroyal seeds but avoid putting them deep in the soil. Just 1/8-inch is enough which means that you should put a very thin layer of soil on the seeds of Pennyroyal.
Pennyroyal grows with a fast pace and it sends shoots from its roots where new Pennyroyal plants grow without any outside help.
Usually, new Pennyroyal plants start growing around an already established plant. So, people usually grow the Pennyroyal plant in containers in order to avoid an undesired spreading of this plant.
You should take a pot which should not be more than 10 inches in size. Now sow the Pennyroyal seeds in this pot and spread a thin layer of soil on the seeds.
You can grow the Pennyroyal in a partial shade or under direct sunlight as this plant survives in almost all weathers and conditions. However, avoid putting it in full shade which can bring harm to its growth.
The important thing that you need to take care of is that you should keep the soil around Pennyroyal seeds a bit moist or damp which will help it grow well even without having water for several days.