Water Willow
Justicia gendarussa
Gendarussa
About this plant
Justicia gendarussa, commonly known as Water Willow, is a fast-growing shrub with slender, willow-like leaves and small white flowers. It is often used in traditional medicine and as an ornamental plant in gardens. It is appreciated for its ability to grow in shaded areas and its attractive foliage.
Taxonomy
- Genus
- Justicia
- Family
- Acanthaceae
- Higher classification
- Order Lamiales
- Plant type
- Shrub
- Lifespan
- Perennial
Origin & Distribution
- Native region
- India, Sri Lanka, Southeast Asia
- Distribution
- Native to South and Southeast Asia; cultivated in tropical and subtropical regions worldwide.
Care
- Light preference
- Partial shade
- Suitable locations
- Indoor, Outdoor, Balcony, Greenhouse
- Preferred window facing
- East-facing, Southeast-facing, South-facing
- Watering frequency
- Moderate
- Watering interval
- 3–7 days
- Humidity
- Normal
- Minimum
- 10 °C
- Maximum
- 35 °C
- Optimal
- 18–28 °C
- USDA hardiness zones
- 9–11
- Soil pH
- 6.0–7.5 (slightly acidic to neutral)
- Soil type
- well-draining loam or potting soil mix
Watering. Water moderately, allowing the top inch of soil to dry out between waterings. Avoid waterlogging to prevent root rot.
Fertilizing. Feed with a balanced liquid fertilizer every 4-6 weeks during the growing season (spring to early autumn). Avoid over-fertilizing to prevent excessive leaf growth with fewer flowers.
This plant is quite tough and easy to care for. It prefers partial shade but can tolerate some sun. It grows quickly and does well in well-draining soil. Overwatering can cause root problems, so let the soil dry out a bit between waterings. Regular pruning helps keep it healthy and bushy.
Propagation
- Propagation methods
- Cuttings, Seeds
- Care difficulty
- Easy
Ornamental features
- Flowering
- Yes
- Flowering period
- spring–summer
Slender green leaves resembling willow leaves and small white tubular flowers.
Toxicity & Safety
- Toxic to humans
- Non-toxic
- Toxic to pets
- Non-toxic
- Weed potential
- Not considered a weed
Generally non-toxic but avoid ingestion and prolonged skin contact with sap to prevent mild irritation.
Allergy information
- Allergy risk
- Low
- Allergy triggers
- Pollen, Sap or latex
- Pollen level
- Low
Justicia gendarussa may cause mild allergic reactions in sensitive individuals, mainly due to its pollen and sap. People with plant allergies should handle it carefully and avoid direct contact with the sap to reduce the chance of skin irritation.
Common problems
If overwatered, the roots may rot. Too much direct sun can cause leaf burn. Occasionally, pests like aphids may appear but are usually manageable.
Uses
Used as an ornamental shrub and in traditional medicine for various treatments.
Notes
Prune regularly to maintain shape and encourage bushier growth. Repot every 2-3 years if grown indoors. Sensitive to frost and cold temperatures.