Pennywort, with its lily pad-like leaves and trailing growth, adds a unique aesthetic to indoor spaces. Its lush foliage makes it a choice for terrariums, humid environments, or as an accent. This plant offers a relatively easy-care experience, suitable for many indoor gardeners.
What is Pennywort (Indoor Variety)
Pennywort refers to several Hydrocotyle species cultivated indoors. Hydrocotyle tripartita (Japanese Pennywort) is popular for its small, clover-shaped leaves that form dense mats. Hydrocotyle vulgaris is another variety with circular, glossy leaves. These plants exhibit a creeping or vining growth, spreading through runners. They thrive in moist, semi-aquatic environments, making them well-suited for humid indoor conditions like terrariums.
Essential Indoor Care for Pennywort
Pennywort prefers bright, indirect light. Too much direct sun can scorch leaves, while insufficient light leads to leggy, sparse growth. An ideal location is near an east-facing window or a few feet from a south or west-facing window.
Pennywort requires consistently moist soil, mimicking its natural bog habitats. It tolerates perpetually wet conditions. Watering methods like bottom watering or keeping the pot in a shallow tray of water help maintain moisture. While it tolerates brief dryness, prolonged lack of water causes wilting.
A well-draining, moisture-retentive soil mix is suitable. Blends often include garden soil, sand, and compost, or cocopeat, sand, and vermicompost. Adding perlite or coarse sand improves drainage while retaining moisture. The plant prefers slightly acidic to neutral soil (pH 5.5-7.5).
High humidity benefits pennywort, reflecting its native wetland environment. Increase indoor humidity with pebble trays, grouping plants, or a room humidifier. The plant thrives in temperatures between 68 and 82°F (20-28°C).
Pennywort does not require heavy fertilization and is sensitive to over-feeding. Apply a balanced, water-soluble fertilizer occasionally, monthly during the growing season (spring and summer), at a diluted strength. Light feeding supports healthy foliage without risking root burn or excessive growth.
Common Problems and Solutions
Yellowing leaves indicate issues like overwatering (leading to root suffocation and nutrient absorption problems), underwatering (dehydration), or nutrient deficiencies (particularly nitrogen). Adjust watering for consistent moisture without waterlogging, and provide balanced fertilizer if a deficiency is suspected.
Stunted growth or browning leaf edges point to environmental stressors. Low humidity is a frequent culprit, as pennywort prefers a moist atmosphere. Insufficient light hinders growth, while too much direct sun causes leaf burn. Ensure adequate humidity and appropriate light exposure to resolve these issues.
Pennywort is pest-resistant, but can be affected by common houseplant pests like aphids or spider mites. Regular inspection of leaves, especially undersides, helps detect infestations early. If pests are found, use gentle organic solutions like insecticidal soap or neem oil.
In wet setups like terrariums or containers without drainage, algae growth can occur. Algae indicates excessive moisture and light, competing for nutrients and blocking light from leaves. Improve air circulation and ensure water is not stagnant to prevent algae. Manual removal is also an option.
Propagating Indoor Pennywort
Propagating indoor pennywort is straightforward. It allows for easy expansion or sharing of plants.
Division involves separating a mature plant into smaller sections. Each new section needs a portion of the root system for successful establishment. Perform this method when repotting.
Stem cuttings are another propagation technique. Cut healthy stems with visible nodes, about one inch below a node. Root these cuttings in water or moist soil. In water, roots emerge from nodes within weeks. For soil rooting, high humidity improves success.
Propagate pennywort during warmer growing seasons: spring, summer, or early autumn. These periods offer optimal temperatures and light for root development and new growth. Provide warmth and consistent moisture, especially for cuttings, to support successful rooting and establishment.