Pennyroyal

Mentha pulegium

Supplied in a 9cm pot

Important: Pennyroyal is grown as an ornamental and aromatic herb only. It is not edible and should never be consumed, as all parts of the plant contain naturally occurring compounds that can be toxic if ingested.

Plant Highlights: Aromatic creeping perennial • Lilac summer flowers • Excellent low-growing ground cover • Attracts bees and pollinating insects • Suitable for borders and containers

Overview

Pennyroyal (Mentha pulegium) is a low-growing herbaceous perennial in the mint family, prized for its strongly aromatic foliage and naturally spreading, mat-forming habit. During summer it produces dense whorls of small lilac to pale purple flowers that provide a valuable nectar source for bees and other pollinating insects, making it an excellent choice for wildlife-friendly planting.

Its creeping growth is well suited to softening the edges of paths, filling gaps between larger plants or covering moist areas of the garden. Although closely related to culinary mints, Pennyroyal is grown solely for its ornamental appearance, fragrance and wildlife value, not for eating or medicinal use. Growing it in a container is an effective way to manage its vigorous spreading habit where space is limited.

Why We Love It

• Forms a fragrant, low-growing carpet of attractive green foliage.

• Summer flowers provide a valuable nectar source for bees and other beneficial insects.

• Excellent for edging borders, wildlife gardens and naturalistic planting schemes.

• Easy to maintain with a light trim after flowering.

• Equally effective in borders, raised beds and containers where its spread can be controlled.

Plant Details

Attribute	Information
Botanical Name	Mentha pulegium
Common Name	Pennyroyal
Plant Type	Herbaceous perennial herb
Foliage	Deciduous, aromatic green leaves
Flowers	Small lilac to pale purple flowers in dense whorls
Flowering Period	Summer
Growth Habit	Low-growing, creeping and mat-forming
Position	Full sun or partial shade
Soil	Fertile, moisture-retentive, well-drained soil
Mature Height	Approximately 10–20cm
Mature Spread	Approximately 30–60cm through creeping stems
Hardiness	RHS H5 – hardy in Irish gardens
Edible Parts	None – not edible

Growing Guide

Position

Plant in full sun or partial shade where it has room to spread naturally, or grow in a container to help restrict its creeping habit.

Watering

Keep the soil consistently moist while the plant is establishing. Once established, water during prolonged dry spells, particularly in containers, while avoiding prolonged waterlogging.

Soil

Pennyroyal performs best in fertile, moisture-retentive, well-drained soil that remains evenly moist throughout the growing season.

Hardiness and Winter Care

Hardy in Irish gardens (RHS H5). The foliage dies back in winter before fresh growth emerges again in spring.

Routine Care

Trim the plant lightly after flowering to keep growth tidy and encourage fresh foliage. Divide established clumps in spring if they become overcrowded or spread beyond their allotted space.

Harvest

Pennyroyal should not be harvested for culinary or medicinal use. Any trimming should be carried out solely for routine plant maintenance.

Perfect For

• Wildlife-friendly gardens.

• Herb gardens grown for ornamental and aromatic interest.

• Edging paths and borders.

• Raised beds and patio containers.

• Moist areas where low-growing ground cover is required.

Good to Know

Despite belonging to the mint family, Pennyroyal is not a culinary herb. All parts of the plant contain the naturally occurring compound pulegone and should not be eaten by people or pets. Its concentrated essential oil is particularly toxic and should never be ingested.

Product Information

• Supplied in a 9cm pot.

• Herbaceous perennial herb.

• Best grown in full sun or partial shade.

• Suitable for wildlife gardens, ornamental herb gardens, containers and ground-cover planting.