← Plant Guides

How to Grow Penny

Wikimedia Commons

Penny

Mentha pulegium

herb

Penny (Pennyroyal) is a low-growing, creeping mint with small aromatic leaves and tiny purple or pink flowers. This aromatic herb has been used for centuries in folk medicine and as a culinary flavoring, though it requires careful handling due to its potent essential oils.

When should you plant Penny in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Penny timeline →

Example Penny timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Penny

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Penny

    Around Jun 1

    ≈ 45 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Penny dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade, 4-6 hours of sunlight daily
💧
Water: Keep soil consistently moist but not waterlogged. Water when top inch of soil becomes dry. More frequent watering needed in hot climates and containers.
📏
Spacing: 12 inches
📅
Days to maturity: 45-60 days from transplant
🌱
Planting depth: Surface sow seeds; transplants at same depth as soil line

Soil

Type: Well-draining loamy or sandy soil
pH: 6.0-7.0
Amendments:
Compost peat moss perlite for drainage

Growing Zones

Find your zone →

Thrives in zones 5-9, tolerates up to zone 10 in cooler microclimates

5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

Sign up free to see if Penny grows in your zone — and get a personalized planting timeline.

Get my Penny timeline →

Growth Stages

1

Germination

1-2 weeks

Tiny seedlings emerge with first true leaves appearing within 7-14 days

Keep soil moist but not waterlogged. Provide light warmth (65-75°F). Thin seedlings to prevent crowding.

2

Vegetative

3-4 weeks

Low-growing plant develops spreading runners and multiple stems with small, oval aromatic leaves

Pinch back growing tips to encourage bushier growth. Water regularly. Feed with balanced liquid fertilizer every 2-3 weeks.

3

Flowering

4-6 weeks

Small purple, pink, or white flowers appear in whorled clusters along the stems

Pinch off flowers if harvesting leaves for stronger leaf flavor, or allow flowering for aesthetic appeal and pollinator attraction.

4

Mature/Harvest Ready

Ongoing until frost

Plant reaches full size with dense foliage and strong aromatic profile; runners may root and spread

Harvest leaves regularly to encourage continued growth. Deadhead spent flowers unless collecting seeds.

Companion Planting

Plan your garden →

Plant with:

Parsley Chives Oregano Thyme Rosemary Chamomile

Avoid planting near:

Mint species (may cross-pollinate and spread aggressively) Fennel Basil

Common Pests

  • Spray with neem oil or insecticidal soap; increase humidity; isolate affected plants

  • Use row covers on young plants; spray with neem oil; remove affected leaves

  • Yellow sticky traps; spray with insecticidal soap or neem oil; improve air circulation

  • Ensure good air circulation; avoid overhead watering; spray with fungicide if severe

Uses

🍳

Mint-flavored beverages and flavoring

Culinary

Fresh or dried leaves can be steeped into teas or added sparingly to beverages and desserts for a minty flavor. Historically used as a culinary mint substitute, though modern culinary use is limited. [source]

💊

Traditional herbal remedy

Medicinal

Used in traditional herbalism for digestive support and respiratory comfort. Contains pulegone and other essential oils. Use only under professional guidance due to potency. [source]

🏠

Natural pest deterrent

Household

The plant's strong aromatic oils make it useful for deterring insects from gardens and indoor spaces. Dried herb can be placed in sachets or used in pest control preparations. [source]

🎨

Dried herb arrangements and potpourri

Craft

Dried pennyroyal adds fragrance to potpourri, herbal sachets, and craft projects. The delicate flowers and leaves retain their scent well when properly dried. [source]

🦋

Pollinator attraction

Wildlife

The flowers attract bees, butterflies, and other beneficial insects to the garden, supporting pollinator populations and garden biodiversity. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Harvest leaves just before flowering for peak flavor and potency. Pinch off stems in the morning after dew dries. For dried pennyroyal, cut stems at base and hang-dry in bundles. Harvest regularly to promote bushier growth. Use fresh within days or dry for longer storage. Note: Use pennyroyal sparingly and cautiously due to concentrated essential oils—not recommended for internal consumption without expert guidance.

Fun Facts

  • 🌱 Pennyroyal has been used since ancient times; the Romans used it in bathing water and medicinally for various ailments.
  • 🌱 The plant's name may derive from 'pulegium' (Latin) or from the Old English 'puliall,' and historically was called 'puliol-royal' (royal thyme).
  • 🌱 Pennyroyal is notably invasive in some regions due to its spreading runners and can rapidly colonize moist areas if not managed.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Deadhead Full Sun Partial Shade Pinch Back Runner True Leaves
Shop Penny plants and related plants at Plant Addicts →

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Penny planting timeline

Tell us your zip code and we'll calculate exactly when to start Penny seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Penny timeline →