Vitex trifolia, often called the Arabian lilac or simpleleaf chastetree, is a fast-growing evergreen shrub native to coastal regions of India and the wider Indo-Pacific. It bears aromatic, grey-green trifoliate leaves that are silvery beneath, releasing a pleasant scent when crushed, and produces airy terminal spikes of small lavender to blue-purple flowers that attract bees and butterflies.
In Indian gardens it is widely grown as an informal hedge, screen or seaside ornamental because it tolerates salt, wind, heat and poor soils. The variegated form is especially popular for its cream-edged foliage. Beyond ornament, the leaves and fruit have a long history in Ayurveda and Siddha medicine.
Specifications
| Family |
Lamiaceae |
| Native region |
Coastal India, Southeast Asia, Australia and the Pacific |
| Mature height |
2-4 m |
| Mature spread |
2-3 m |
| Growth rate |
Fast |
| Foliage |
Evergreen, aromatic, grey-green trifoliate leaves, silvery beneath |
| Flower colour |
Lavender to blue-purple |
| Flower season |
Mainly monsoon to autumn (Jun-Oct), sporadic year-round in warm areas |
| Climate zone |
Tropical and subtropical; suited to most of India |
Care guide
| Sunlight |
Full sun for best flowering and dense growth; tolerates light partial shade. |
| Watering |
Moderate. Water when the top few cm of soil dry out; established plants are quite drought-tolerant. |
| Soil / mix |
Well-drained sandy or loamy soil; tolerates poor and saline coastal soils. Avoid waterlogging. |
| Temperature |
Thrives in 20-38 C. Loves heat; protect from hard frost in north Indian winters. |
| Humidity |
Adapts to both humid coastal and drier inland conditions. |
| Fertilizer |
Light feeder. Apply compost or a balanced fertilizer once or twice during the growing season. |
| Pruning |
Responds very well to pruning; trim after flowering to keep it dense as a hedge or shape. |
| Repotting |
If container-grown, repot every 2-3 years or when root-bound, into a larger well-drained pot. |
| Propagation |
Easily from semi-hardwood stem cuttings; also by seed and layering. |
| Pests & problems |
Generally hardy; occasional mealybugs, aphids or leaf-eating caterpillars. Treat with neem oil. |
| Toxicity / safety |
Not known to be significantly toxic; leaves and fruit are used in traditional Indian medicine. Not listed among major pet-toxic plants, but not intended for casual consumption. |
| Difficulty |
Easy |
Uses
<ul><li>Popular salt- and wind-tolerant ornamental hedge or screen for coastal and urban Indian gardens.</li><li>Aromatic silvery foliage and blue flower spikes used as cut foliage and to attract pollinators.</li><li>Leaves and fruit have a long traditional role in Ayurveda and Siddha for joint pain, headaches and respiratory complaints.</li><li>Crushed leaves are traditionally used as an insect and mosquito repellent.</li></ul>
Growing tips
<p>Plant at the start of the monsoon (Jun-Jul) so it establishes with natural rainfall. Choose a sunny, open spot with free-draining soil.</p><p>In summer give occasional deep watering; in the rains ensure drainage to avoid root rot. Pinch and trim young plants to encourage a bushy form, and prune lightly after each flush of bloom. In north India, shelter from severe winter frost.</p>
