Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called mosquito plant and pudding grass, is a species of flowering plant in the mint family, Lamiaceae, native to Europe, North Africa, and the Middle East. Crushed pennyroyal leaves emit a very strong fragrance similar to spearmint. Pennyroyal is a traditional folk remedy, emmenagogue, abortifacient, and culinary herb, but is toxic to the liver and has caused some deaths. European pennyroyal is related to an American species, Hedeoma pulegioides. Though they differ in genera, they share similar chemical properties.
Pennyroyal generally has strong disease resistance and is not commonly affected by illnesses. Still, it can be vulnerable to pests and diseases that are present in its surroundings. Such infections are usually mild. In terms of care, this plant requires a moderate amount of maintenance. It should be pruned regularly to preserve a neat appearance and encourage healthy growth. Fertilizing can also aid in promoting blooms. Pennyroyal is suitable for anyone with an outdoor area, like a garden or patio, and does not demand extensive gardening experience. It may need more attention when grown indoors.
How to keep Mentha Pulegium.
Light
Pennyroyal grows best when given abundant sunlight, though it can tolerate shorter periods of light. Continuous sun exposure promotes vigorous growth, while inadequate light can slow its development. Without sufficient light, the plant may become stunted.
Water
Pennyroyal flourishes in moist environments because of its origins, which allow it to retain water effectively. To keep it healthy, it requires balanced watering each week, ensuring it is neither overwatered nor too dry. As an outdoor herb, its growth is closely tied to the availability of water. Regular rainfall is vital for its seasonal development.
Humidity
This plant will thrive in moderate humidity, which is probably the level in your home. However, misting it a few times a week can be very beneficial. Make sure the room has good ventilation.
Temperature
Pennyroyal is native to cool temperate regions and prefers temperatures between 50 to 95 ℉ (10 to 35 ℃). In summer it may need shading or mulching to retain soil moisture and prevent the plant from wilting. In winter it may require protection from severe cold.
Fertilizer
One fertilizer application in spring is generally enough for pennyroyal, though several feedings can produce the best growth. Apply fertilizer roughly every month to a month and a half. Fertilizing improves the leaves’ appearance and performance, supporting even color and a healthy texture. It also encourages root development and better nutrient uptake for the plant’s long-term health.
Pruning
Pennyroyal is appreciated for its fragrant scent and purple flowers, and it benefits from regular pruning. The best time to prune is from early to late spring. After the plant has flowered, remove up to one-third of its height. This helps to encourage bushiness, control its invasiveness, and improve airflow. Make sure to use sharp, clean tools for precise cuts.
Pot & Repot
When repotting Pennyroyal, select a pot 1-2 inches (2.5–5.1 cm) larger with good drainage. Use a well-draining potting mix. Repot in spring or fall, making sure the root ball sits slightly below the rim of the flower pot. Water thoroughly after repotting and place in a warm spot with indirect sunlight.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Perennial
- Genus
- Mentha
- Family
- Lamiaceae
- Hardiness Zone
- 6-9
- Mature Height
- 10 cm
- Mature Spread
- 61 cm
- Leaf Color
- Green
- Leaf Type
- Deciduous
- Flower Color
- Lavender, Pink
- Flower Size
- 1.02 cm to 1.52 cm
- Bloom Time
- Early summer, Mid summer
- Planting Time
- Spring
- Harvest Time
- Mid summer
- Native Area
- Libya, Egypt, Turkey, Sweden, Austria, Slovakia, Montenegro, Slovenia, Morocco, Croatia, Russia, Germany, Ethiopia, Romania, Belgium, Portugal, Netherlands, France, Tajikistan, Tunisia, Czech Republic, Cyprus, Bulgaria, Poland, Armenia, Greece, Ukraine, Serbia, Lebanon, Norway, Syria, Italy, Kazakhstan, Spain, Switzerland, Denmark, Finland, Iran, Albania, Ireland, United Kingdom, Hungary, Algeria, Azerbaijan, Turkmenistan
Other names.
Reader questions.
How do I water my Pennyroyal plant in the best way possible?
To properly water the Pennyroyal plant, it is best to use filtered water at room temperature. Tap water may contain harmful particles, so filtering it is ideal. Also, the water should be at room temperature or slightly warmer to avoid shocking the plant, as it is accustomed to a warm environment. Overhead watering should be avoided, as it can lead to problems with the foliage. Instead, water the plant by pouring filtered room temperature water onto the soil until it is thoroughly soaked. This will benefit the plant by moisturizing the roots and aiding in the spread of nutrients throughout the soil.
Why should I add fertilizer to my Pennyroyal plant?
The main structure of the Pennyroyal consists of its leaves, and proper fertilization is essential for maintaining their appearance and function. By fertilizing the plant correctly, you can ensure that the leaves maintain consistent color and a healthy texture. Additionally, fertilization benefits the Pennyroyal by promoting the growth of new roots and maintaining the existing ones underground. This not only keeps the plant healthy at present but also improves its ability to absorb nutrients from the soil in the future.
How much sunlight does Pennyroyal need?
Pennyroyal requires full sun to thrive, meaning it needs more than 6 hours of sunlight daily. However, it can also grow in partial sun, receiving about 3-6 hours of sunlight. It's crucial to watch how sunlight moves through your garden to choose spots that offer the right balance of light and shade, ensuring the plant's happiness and healthy growth.
What is Pennyroyal and where is it native to?
Pennyroyal, botanically known as Mentha pulegium, is native to cool temperate regions. It thrives in temperatures between 50 to 95°F (10 to 35°C), demonstrating strong cold resistance. Despite its resilience in cool conditions, during the hot summer months, Pennyroyal may require shading or mulching to maintain soil moisture and prevent wilting. In contrast, during winter, it might need protection from severe cold, although special frost protection measures are not usually necessary.
What should I do if I give my Pennyroyal plant too much or too little water?
Overwatering is a more common issue than underwatering for Pennyroyal plants. When Pennyroyal receives too much water, its stems and leaves may wilt and turn yellow. Overwatering for too long can also lead to diseases like root rot, mold, and mildew, which can kill the plant. Underwatering is less common, as Pennyroyal has good drought tolerance. However, if underwatering occurs, the leaves may become brittle and brown. It is important to recognize the signs of overwatering early and reduce watering immediately. Check the soil quality of your Pennyroyal plant, and if it drains poorly, replace it with a well-draining potting mix. If you notice signs of underwatering, simply water more regularly until the signs improve.
When should I fertilize my Pennyroyal plant for the best results?
When you grow your Pennyroyal outdoors, it will start growing new leaves in early spring. This is when you should start fertilizing it. Usually, one application of fertilizer is enough for the Pennyroyal to do well in the spring. However, if you want to maximize its growth, you can fertilize it multiple times throughout the spring and early summer. In this case, you can feed the Pennyroyal once every month to a month and a half.
Can Pennyroyal grow with artificial lighting?
Yes, Pennyroyal can grow under artificial lighting, especially when natural sunlight is insufficient, such as during winter or in less sunny indoor spaces. Indoor plants benefit from artificial lights, promoting faster and healthier growth. LED lights are recommended due to their ability to mimic the specific wavelengths of light plants need. For full sun plants like Pennyroyal, aim for 30-50W/sq ft of light, positioning the light source 12-36 inches above the plant and ensuring it receives 8-12 hours of light per day.
How should Pennyroyal be cared for in winter?
During the winter, Pennyroyal may require protection from severe cold if temperatures are expected to drop below its growth limit. While it has strong cold resistance and usually doesn't need extra frost protection, it's important to cover the plant with materials such as soil or straw to shield it from extreme cold. Additionally, before the first freeze in autumn, watering the plant abundantly to ensure the soil remains moist can help prevent drought and water scarcity during the colder months and into early spring.
How many times a week should I water my Pennyroyal plant?
If your Pennyroyal plant is in a pot, the best way to determine if it needs watering is to stick your finger into the soil. If the top two to three inches of soil are dry, it's time to water it. The same method can be used if you're growing Pennyroyal outdoors in the ground. When the first few inches of soil have dried out, it's time to water. In spring and early fall, you'll typically need to water this plant about once a week. During extremely hot weather, you may need to water it twice a week or more. However, mature and well-established Pennyroyal plants are quite resilient and can tolerate drought.
When is it best not to fertilize my Pennyroyal?
During the late fall and winter, your Pennyroyal will go into a dormant phase and stop growing. It's best not to fertilize your Pennyroyal during this time. In the spring and summer, if you choose to fertilize, you should gradually reduce the amount as summer approaches because the growth rate of the Pennyroyal will slow down. In general, it's not a good idea to fertilize your Pennyroyal when the weather is unusually hot or the soil is very dry. Doing so can stress the Pennyroyal and cause it to die prematurely.
What are the signs of insufficient light in Pennyroyal?
When Pennyroyal doesn't receive enough light, it may exhibit several symptoms: smaller new leaves, leggy or sparse growth, faster leaf drop, slower or no new growth, and leaves that appear paler or develop irregular color patterns due to a lack of chlorophyll. This can lead to chlorosis (yellowing of leaves), sunscald, leaf curling, wilting, and leaf scorching. These signs indicate the plant is struggling with the light conditions and needs more sunlight.
What are the signs of low temperature distress in Pennyroyal, and how can they be addressed?
Pennyroyal is cold-tolerant and does best when temperatures remain above its acceptable minimum growth temperature. If temperatures during winter stay above the tolerable minimum but fall below the growth limit, you might not observe noticeable changes immediately; however, there could be a decrease in sprouting or even failure to sprout during spring. To address this issue, in spring, remove any parts of the plant that have failed to sprout.
