Pennywort
Overview
Pennywort usually refers to Centella asiatica, a low, creeping herb with rounded leaves that loves warm, moist conditions. It grows well as a groundcover or in containers with partial shade and rich, damp soil. Often eaten fresh in Asian salads and drinks, it’s also valued in traditional herbal medicine.
Characteristics
Known for its low, creeping growth habit, round coin-like leaves, preference for consistently moist soils, and traditional use in both cuisine and herbal medicine.
Region
Commonly found and grown in tropical and subtropical Asia (India, Sri Lanka, Southeast Asia, southern China, Indonesia) and, for marsh types, in cool-temperate wetlands across Western Europe and similar climates.
Natural Habitat
Commonly found in damp grasslands, along riverbanks, rice paddies, and other moist or swampy lowland areas.
Cultivation
Prefers partial shade to dappled sun, consistently moist to wet soil (never fully dry), in fertile, organic-rich loam that drains well but retains moisture; some species tolerate shallow standing water.
Uses and Benefits
Fresh leaves of Centella asiatica are popular in Sri Lankan sambols, Southeast Asian salads, and cooling green drinks, bringing a mild, slightly bitter flavor that pairs well with chili, lime, and coconut.89
- Culinary: Use young leaves raw in salads, smoothies, or as a garnish. Older leaves can be chopped into rice dishes or light curries.
- Skin support: Extracts are used in creams and gels to help with minor wounds, scars, and stretch marks, thanks to compounds that encourage collagen formation.1112
- Circulation: Standardized extracts have been studied for easing leg heaviness, swelling, and poor venous tone.13
- Mood and mind: Long valued in Ayurveda and Traditional Chinese Medicine as a “brain tonic,” with modern research exploring its antioxidant and neuroprotective effects.414
Many home herbalists sip light infusions or add a few fresh leaves to daily meals rather than using high doses, which helps keep intake gentle and steady over time.15
Cultivation Tips
For home gardens, focus on Centella asiatica, which thrives in warmth and steady moisture. In cooler regions, treat it as a tender perennial in pots you can move indoors when frost threatens.56
Give plants loose, fertile soil and light shade, then keep the surface just damp rather than waterlogged. A thin mulch helps lock in moisture and keeps leaves clean for kitchen use.46
- Soil: Rich, composted loam; slightly acidic to neutral (pH 5.5–7.0).
- Light: Morning sun, afternoon shade; avoid harsh midday sun unless soil stays very moist.
- Water: Never let plants fully dry out; water when the top layer feels just dry.
- Spacing: 15–30 cm apart so runners can knit into a soft mat.
- Feeding: Light applications of balanced organic fertilizer in the growing season.
Start new plants by dividing rooted runners or pressing stolon segments with visible nodes into damp soil until they root.6 Harvest leaves often by snipping the outer growth; this keeps the clump low, lush, and tender.
In wet spots or pond edges, Hydrocotyle species prefer saturated soil or very shallow water. Grow them in baskets or lined beds to prevent escape into natural waterways, as some pennyworts can spread aggressively.316
Companion Planting
Companion planting with pennywort is all about matching its love of moisture and gentle shade.
For garden pennywort or gotu kola (Centella asiatica), tuck it beneath taller herbs like lemongrass, ginger, or small fruit bushes. These cast light shade, helping keep the soil cool and damp while pennywort forms a living mulch that suppresses weeds and slows evaporation.6
It also pairs well with other moisture-loving kitchen herbs such as mint (Mentha spp.) and lemon balm (Melissa officinalis), though you may want containers or edging to stop these vigorous spreaders from overwhelming it. In cooler months, grow it alongside coriander/cilantro (Coriandrum sativum) and leafy salad greens under partial shade netting for a lush, easy-to-harvest herb bed.6
Marsh pennywort (Hydrocotyle vulgaris) fits naturally into pond and bog gardens. Combine it with watercress (Nasturtium officinale), marsh marigold (Caltha palustris), iris, or hosta around damp edges.37 Its creeping habit knits the soil, fills bare patches, and adds a soft green carpet beneath taller plants, creating a stable, wildlife-friendly waterside community.
Seasonal Considerations
Seasonal care depends on whether you’re growing gotu kola or one of the marsh pennyworts, and on how cold your winters get.
- Spring: As soil warms, new runners surge. Feed lightly with compost tea, keep moisture steady, and start regular leaf harvests once plants are dense and bright green.6
- Summer: In hot climates, offer afternoon shade and extra water to prevent leaf scorch on Centella asiatica.4 Marsh pennywort will relish the heat if water stays cool and abundant.
- Autumn: Growth slows as nights cool. Take a final generous harvest, then thin and tidy mats so plants go into winter healthy.
- Winter: In frost-free areas, growth continues at a gentler pace. In colder regions, overwinter gotu kola in containers indoors, keeping soil just moist, while hardy marsh pennywort can rest outdoors in unfrozen, saturated ground.57
Issues and Troubleshooting
Weak, yellowing growth
Often caused by low fertility, cramped roots, or too much sun. Feed with a dilute, balanced organic fertilizer and add compost. Move gotu kola into partial shade; marsh pennywort can handle more sun if water stays constant.56
Leaf scorch or curling
Leaves crisp at the edges or curl under when soil dries out or heat is high. Increase watering, mulch the soil, and provide afternoon shade, especially for Centella asiatica.46
Rot at stems or roots
If plants collapse from the base, soil is likely waterlogged but poorly aerated. Improve drainage in pots, use a loamy mix, and avoid letting containers sit in stagnant water.6
Slug and snail damage
Ragged holes and missing seedlings indicate grazing.
Use hand-picking at dusk, beer traps, copper tape, or rough mulches (crushed eggshells) as barriers.7
Overgrowth and invasiveness
Rapid runners can smother neighbors or escape into waterways.16 Grow in containers or lined beds, trim regularly, and never dump trimmings in natural ponds or streams.
History and Folklore
Pennywort has woven through many cultures under different names. In Ayurveda, gotu kola pennywort is celebrated as a rasayana herb, linked with long life, sharp memory, and spiritual growth.4 Legends tell of sages and yogis nibbling the leaves to deepen meditation and keep the mind clear.
In Chinese tradition, pennywort (ji xue cao) appears in herbal records as a purifier and healer, and later stories claim the herbalist Li Ching-Yuen lived to an extraordinary age with its help, feeding its image as an “elixir of life.”1718 Marsh pennywort in Europe has a quieter history, appearing in old herbals as a simple wetland remedy and sharing the misty, mysterious aura of fens and bogs.10
References
1. Plunkett, Gregory M., and Porter P. Lowry II. “Relationships among Apiaceae Subfamilies and Tribal Circumscriptions Based on Phylogenetic Analyses of Molecular Data.” American Journal of Botany, vol. 88, no. 10, 2001, pp. 1888–1905. JSTOR, https://www.jstor.org/stable/3558364
2. van Wyk, Ben-Erik. Culinary Herbs and Spices of the World. University of Chicago Press, 2014.
3. Stace, Clive. New Flora of the British Isles. 4th ed., Cambridge UP, 2019.
4. Sharma, P. V. Dravyaguna Vijnana: Material Medica (Vegetable Drugs). Vol. 2, Chaukhambha Bharati Academy, 2001.
5. Brickell, Christopher, editor. The Royal Horticultural Society A–Z Encyclopedia of Garden Plants. 4th ed., Dorling Kindersley, 2016.
6. Ranade, Rahul, et al. “Cultivation Practices and Agronomic Requirements of Centella asiatica (L.) Urban: A Review.” Journal of Medicinal Plants Studies, vol. 5, no. 6, 2017, pp. 23–28.
7. Haslam, Sylvia M. A Flora of the British Isles: Aquatic and Wetland Plants. Forrest Text, 2007.
8. Jayaweera, D. M. A. Medicinal Plants (Indigenous and Exotic) Used in Ceylon. Vol. 3, National Science Council of Sri Lanka, 1982.
9. Van Thuoc, Dang, et al. “Traditional Vietnamese Herbal Medicine: A Brief Overview.” Integrative Medicine Research, vol. 6, no. 4, 2017, pp. 411–420.
10. Grigson, Geoffrey. The Englishman’s Flora. Helicon Press, 1958.
11. Brinkhaus, Benno, et al. “Chemical, Pharmacological and Clinical Profile of the East Asian Medical Plant Centella asiatica.” Phytomedicine, vol. 7, no. 5, 2000, pp. 427–448.
12. Byun, Sang Wook, et al. “Efficacy of Centella asiatica Extract in the Treatment of Scars: A Systematic Review.” International Wound Journal, vol. 16, no. 1, 2019, pp. 1–10.
13. Cesarone, Mario R., et al. “Centella asiatica (L.) Urban (Hydrocotyle asiatica L.) in Chronic Venous Insufficiency and Microangiopathy: An Experimental and Clinical Study.” Angiology, vol. 43, no. 6, 1992, pp. 507–513.
14. Wattanathorn, Jintanaporn, et al. “Evaluation of Neuroprotective Effect of Centella asiatica in Alzheimer’s Disease: From In Vitro to Clinical Trial.” Evidence-Based Complementary and Alternative Medicine, vol. 2019, 2019, Article ID 3815952.
15. Tiwari, Rajeev, et al. “Safety Assessment of Centella asiatica Extract: A Review.” International Journal of Toxicology, vol. 30, no. 6, 2011, pp. 567–576.
16. Global Invasive Species Database. “Hydrocotyle ranunculoides (Floating Pennywort).” IUCN/ISSG, http://www.iucngisd.org/gisd/speciesname/Hydrocotyle+ranunculoides. Accessed 10 Dec. 2024.
17. Bensky, Dan, et al. Chinese Herbal Medicine: Materia Medica. 3rd ed., Eastland Press, 2004.
18. Yang, Xiaoli, and Hong Kong Baptist University School of Chinese Medicine. “Longevity Herbs in Chinese History and Culture.” Journal of Chinese Medicine and Culture, vol. 1, no. 2, 2018, pp. 45–53.
Nicolas Duval
Nicolas is a passionate advocate for nature and the art of wildcrafting. His dedication shines through in Wildcraftia, a website he meticulously crafted to serve as a haven for nature enthusiasts worldwide. Driven by a deep appreciation for nature’s connection to humanity, Nicolas embarked on his journey in 2011 with SmokableHerbs, a platform showcasing his love for nature’s bounty. Building upon this foundation, he established Smokably, a thriving online store offering premium herbs and blends to a global audience.