How to Grow Whorled Pennywort

iNaturalist

Whorled Pennywort

Hydrocotyle verticillata

herb

Hydrocotyle verticillata is a small aquatic or semi-aquatic herb with distinctive whorled leaves arranged in circular patterns around the stem. Native to North America, it grows in shallow water and wet environments, forming dense mats of delicate foliage. It is commonly used in aquariums and water gardens for its ornamental appearance and water-purifying properties.

When should you plant Whorled Pennywort 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 Whorled Pennywort timeline →

Example Whorled Pennywort timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Whorled Pennywort

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Whorled Pennywort

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

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

Growing Conditions

☀️
Sun: Moderate to bright indirect light; 8-12 hours of light daily in aquariums or water gardens
💧
Water: Requires consistently wet to submerged conditions; grows best in 2-8 inches of water. Maintain water temperature between 60-80°F (15-27°C). In outdoor water gardens, ensure water circulation to prevent stagnation.
📏
Spacing: 6-12 inches apart to allow for horizontal spreading inches
📅
Days to maturity: 20-40 days to establish visible growth; full mat formation in 2-3 months
🌱
Planting depth: Plant runners horizontally at substrate surface; bury stolons 1-2 inches deep

Soil

Type: Nutrient-rich aquatic soil or submerged substrate; can also grow in wet, muddy soil
pH: 6.0-7.5
Amendments:
Aquarium plant fertilizer Peat moss Organic compost Micronutrient supplements (iron, potassium)

Growing Zones

Find your zone →

Thrives in zones 5-10, prefers warmer climates but can tolerate cooler zones

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

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

Get my Whorled Pennywort timeline →

Growth Stages

1

Establishment

1-2 weeks

New sprigs showing initial rooting; small whorled leaves emerging

Ensure stable water parameters and gentle water movement. Avoid strong currents that can uproot new plants. Provide consistent lighting.

2

Vegetative Growth

3-6 weeks

Rapid stem elongation with successive whorled leaves forming at regular intervals; horizontal runners (stolons) developing

Fertilize regularly with aquatic plant fertilizer. Maintain adequate light and water circulation. Prune taller stems to encourage bushier growth.

3

Maturation

4-8 weeks

Dense matte or carpeting growth pattern with well-established root systems; multiple stems and runners spreading

Continue regular fertilization. Thin out overly dense areas to prevent decay underneath. Monitor for algae competition.

4

Flowering

Variable, typically not observed in fully submerged settings

Small, inconspicuous white or greenish flowers may emerge above the water line on mature plants (rare in submerged conditions)

Optional stage; most aquatic specimens remain in vegetative form. Allow flowering only if desired for seed propagation.

5

Propagation

Continuous during growing season

Runners producing plantlets at nodes; fragmentation possible for asexual reproduction

Collect runners with rooted nodes and replant to expand coverage. Separate and relocate plantlets to new areas.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Aggressive fast-growing stem plants (may compete for nutrients) Dense shade-producing plants (reduces light availability) Plants requiring still water (if using high-flow systems)

Common Pests

  • Improve water circulation, reduce excess nutrients, increase plant density to outcompete algae, use algae-eating fish or shrimp, perform regular water changes

  • Manual removal, reduce phosphate levels, improve CO2 balance, increase plant mass, use hydrogen peroxide spot treatment

  • Manual removal, reduce feeding of other organisms, introduce snail-eating fish, limit decaying plant matter

  • Ensure adequate water circulation, avoid burying stems too deeply, maintain proper substrate aeration, remove affected portions

Uses

🍳

Salads and Fresh Garnish

Culinary

Young whorled leaves can be added fresh to salads, providing a mild, slightly bitter herbal flavor. Often used as an ornamental and edible garnish in Asian cuisine. [source]

💊

Traditional Diuretic and Anti-inflammatory

Medicinal

Used in traditional medicine systems, particularly Ayurveda and Traditional Chinese Medicine, to support kidney function, reduce water retention, and address inflammatory conditions. [source]

🏠

Water Purification

Household

Acts as a natural biofilter in aquariums and water gardens, absorbing excess nutrients (nitrogen and phosphorus) and helping to reduce algae growth by outcompeting algae for resources. [source]

🎨

Aquascaping and Aquarium Design

Craft

Widely used in freshwater aquariums and planted water gardens for its delicate, carpet-like growth pattern and ornamental appearance; popular in aquascaping competitions. [source]

🦋

Habitat for Aquatic Fauna

Wildlife

Provides shelter, foraging grounds, and breeding substrate for aquatic invertebrates, fish fry, and beneficial microorganisms in water gardens and aquatic ecosystems. [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 stems and runners as needed by gently pulling or cutting with scissors. Can be harvested continuously during growing season. Best harvested in morning. Remove no more than one-third of plant mass at a time to allow recovery. Use harvested portions for propagation or as culinary/medicinal preparations.

Fun Facts

  • 🌱 Hydrocotyle verticillata is one of the most fast-growing aquatic plants available, capable of doubling biomass in just 1-2 weeks under ideal conditions, making it excellent for rapidly establishing aquascapes.
  • 🌱 The name 'pennywort' refers to the coin-like shape of its leaves, while 'verticillata' describes the distinctive whorled (circular) leaf arrangement that makes it instantly recognizable among aquatic plants.
  • 🌱 In its native North American wetlands, this species plays an important role in stabilizing sediments and filtering water, and is now cultivated globally in aquaculture as both an ornamental and functional bioremediator.

Gardening Terms

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

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Whorled Pennywort planting timeline

Tell us your zip code and we'll calculate exactly when to start Whorled Pennywort 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 Whorled Pennywort timeline →