The Spruce / Adrienne Legault
Pennyroyal (Mentha pulegium) is a spreading plant with upright stems.
It produce whorls of pale purple flowers in mid to late summer.
The small oval leaves are medium green and droop from stalks that can grow to a foot tall.
The Spruce / Adrienne Legault
Pennyroyal is generally planted in the spring after alldanger of frosthas passed but while the soil is still cool.
The oils of this plant are toxic to humans and pets.
Gardeners new to growing herbs are sure to find success with vigorous pennyroyal plants.
The Spruce / Adrienne Legault
Warning
Pennyroyal is considered an invasive species, mostly in parts of California and Oregon.
Pennyroyal has no soil pH preference, growing equally well in acidic, neutral, or slightly alkaline soil.
Water
Regular moisture is an important element to a thriving pennyroyal plant.
The Spruce / Adrienne Legault
The surface of the soil should always feel moist to the touch.
Pennyroyal grows well in damp areas like stream banks or low-lying depressions in the landscape.
Temperature and Humidity
Pennyroyal grows equally well in areas with cool or hot summers.
The Spruce / Adrienne Legault
Fertilizer
Chemical fertilizers aren’t necessary to grow healthy pennyroyal plants.
In fact, too much fertilizer can reduce flowering in pennyroyal plants.
Pruning
Cutting back your pennyroyal plants is an important part of keeping the plant’s growth contained.
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Do this more frequently in wet, warm weatherat least weekly.
Cutting back pennyroyal plants after flowering helps to keep the plant tidy as well.
Give them a head start indoors by planting four to six weeks before the last frost date.
At a temperature of around 68 degrees Fahrenheit, the seeds will sprout within about 21 days.
Transplant the seedlings outdoors after all danger of frost has passed, spacing them 18 to 24 inches apart.
Pennyroyal plants will grow in pots of any size and any material, in a standard commercial potting mix.
see to it the container has good drainage holes.
They are pretty tolerant of beingroot-bound.
Potted specimens should be moved to a sheltered location for the winter.
Powdery mildewand mint rust can trouble plants growing in crowded, damp, shady conditions.
Keep your pennyroyal plants disease-free with adequate sun and spacing, and by planting them in well-draining soil.
If fungal diseases continue to be an issue, consider thinning out your plant to improve airflow.
Yes, the pennyroyal plant is good for repelling insects.
The plant is used frequently in natural pest repellents.
Make use of the pruned stems from your pennyroyal wherever unwanted insects are a problem.
Pennyroyal is a traditional cottage garden plant, but it is not a particularly attractive specimen.
It is mostly grown as an insect-repelling plant.
Its habit of steady spread means that a colony of pennyroyal plants will continue indefinitely.
While most mints are grown for their scent, some are used more for their ornamental value.
It is suitable for USDA zones 5 to 10.
However, like most mints, this is also an aggressive grower.
Pennyroyal.Invasive Plant Atlas of the United States.
Pennyroyal Oil Poisoning in Dogs.PetMD.
