Pennyroyal mint. Cultivation care and properties

Pennyroyal will be together with chamomile (with the permission of the tea) one of the queens of the infusions. And it has a lot to say because its properties are more than proven as we will see later and its cultivation is really simple. Let’s learn a little more about this variety of mint and why it is so appreciated.


We are so into the western world of packaged food that we think of pennyroyal and the first image that comes to mind is not the plant, but the infusion bag in a mug of hot water. But it is a plant! and as such it can be sown, taken care of, collect dry and infused in a natural way. Do you want to grow your own pennyroyal mint? Go for it.

First of all tell you that the name of pennyroyal comes directly from its taxonomic or scientific name, Mentha pulegium. It will be one of the common names most similar to the scientific name without a doubt. The genus Mentha is a rather small genus. Today it comprises 42 species accepted within more than 2,500 different names of species that end up being synonymous with these 42 and many other derived varieties.

Pennyroyal has its origin in North Africa, the Middle East and Europe and the current distribution is mainly focused on this continent, spreading overwhelmingly in Spain. There is no corner of Spain in which it is not present, neither by latitude, nor by climate as we can see in the following image. Certain gaps can be observed in the areas of plateau climate or Mediterranean climates that can be too dry, because as we will see, it is a species that needs moist soils to thrive.

It is a perennial, creeping plant, with rhizomatous roots , short (does not rise more than 40-50 cm) and is quite upholstery if it gets out of control. Its opposite, slightly toothed, dark green leaves easily cover surfaces. Its purple flower stalks are a nice pop of color at peak bloom in the summer.

Pennyroyal mint distribution in Spain. Source:


Pennyroyal can be sown in a seedbed, with small alveoli with a little substrate or mulch, rich in organic matter. We will have to plant one or a couple of seeds in each alveolus. We emphasize this because the seeds are extremely small! You have to cover it with a little soil and water it so that it settles. Once they germinate, it is a matter of transplanting to the final place.

Germination is slow but the seed has great germination power . Virtually all the plants will come out ahead. It is very very rustic, nothing delicate in that sense. It takes about a month to germinate.

You can also plant it directly in the orchard or garden at the beginning of spring and during. A reseeding should be done every year, taking seed from the previous year. It is a very vigorous plant and it colonizes a lot so it is preferable to harvest and “sweep” all traces of it until the following year. Being rhizomatous it is quite persistent and our recommendation is to plant it in a confined place such as a flowerpot or planter so that the crop does not get out of hand if you cannot be very aware of the garden.

Mint poleo ( Mentha pulegium ) wild. Photo of: born1945



Being a perennial plant, it supports quite extreme cold and no apparent damage is observed up to -20ºC, so it is perfectly cultivable in high mountain areas. It will take it worse in hot climates as it needs plenty of water to get through the hot flashes.

The sun exposure can be total or partial in a temperate-cold climate. In Mediterranean climates it will not support so much exposure so we recommend a semi-shady area and frequent waterings.


Supports all types of floors. It is an all-terrain plant. Loamy, silty, clayey, sandy … it also has no problems growing in alkaline, acidic or neutral soils. It is a marvel of a plant in this sense so there is nothing more to say about it. If it is planted in a pot or indoors, any universal substrate is enough.


This is the delicate point of the cultivation of pennyroyal. It needs frequent waterings . Remember: frequent is not abundant. Keep the soil moist, that’s all. In the summer months a minimum of 2-3 weekly irrigations depending on the weather, even some more on days that are very hot and if it is in a pot or planter even more since they have less root space to absorb and therefore they will perspire worse.


Pennyroyal can be harvested throughout the year, even during flowering periods, although you should know that most of the active ingredients are found in the leaf. We simply cut stems and group them into twigs with a string . In a dry place they are hung upside down and we let them dry for a few days. In summer in 4-5 days we have it dry.

Pennyroyal mint flower. Photo by: Katya

If we collect at the time of flowering, we can leave some to obtain seed and plant the following year, although being a rhizomatous plant we can also propagate it by division from spring to autumn. In any case, it is not a plant that we should worry about multiplying. It is very aggressive and covers terrain quickly. Normally you have to do the opposite, delimit the space by pruning.



Among the most common pests we find spider mites and caterpillars . Diseases can be susceptible to fungi such as downy mildew and to a type of rust , Puccinia menthae. This particular fungus does not only affect pennyroyal. Also to other species of the genus Mentha and other genera of plants commonly consumed such as marjoram or savory.

In humid environments, it is difficult to control cryptogamic diseases without systemic fungicides once they appear, but in somewhat drier environments, not wetting the leaves can be enough providing a good dose of irrigation in the soil.

Although these problems can appear, pennyroyal is not a plant too susceptible to pests and diseases in general.


Why is pennyroyal so widely used? What active principles make it up? We are going to answer all this.

In the first place, its active principles are mainly menthol and pulegone, although there are more. Common mint has them too. Pulegone is an organic molecule called a terpene. It has a pleasant aroma and its extract is used for perfumery, for example. But we must warn that this monoterpene in high doses is toxic with serious consequences for the liver, especially if there is liver disease. Do not be scared because taking the infusion, the dose is not much less high. In addition, with the heat of the water in the infusion, it is totally harmless and the drying process of the plant also partially degrades this molecule.

In general, mints have important percentages of vitamins of group B in general (B1, B2, B3), highlighting their content in B2. The B group vitamins play a great role in the metabolic action of the cells of our body and specifically vitamin B2 (riboflavin) influences the absorption of fat and proteins as well as the formation of red blood cells.

Be careful with the essential oil because the concentration of pulegone is very high and its ingestion can cause serious liver and kidney disorders whose outcome can be fatal.


We all know that heavy digestions or stomach aches can be soothed with an infusion of pennyroyal. And it is that it has carminative properties , that is, it eliminates excess gas and helps in the digestive process by stimulating the secretion of gastric juices in addition to relaxing the digestive tract and avoiding annoying intestinal ailments.


In general, any infusion (except those with stimulants such as tea) usually have a relaxing effect , due to the heat that we introduce into our body. That is why soups also taste good. The aroma, warming your hands with the cup and part of the active principles of many plants help to generate that relaxing sensation. It is clear that there are species with much more relaxing effects than pennyroyal such as valerian among others.


Menthol, which is another of the abundant active principles of pennyroyal, has already been shown to be active and passive for its expectorant and decongestant effect on flu and catarrhal processes. Its effect is mild on pennyroyal but it helps.


This is neither more nor less than promoting menstruation. It has been used traditionally to regulate the menstrual process and even with abortifacient properties. That is why its use during pregnancy is totally discouraged .

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