Ocimum tenuiflorum, commonly known as Holy Basil or Tulsi, is a revered plant in many cultures, particularly in India, where it is grown for spiritual and medicinal purposes. In the Australian garden, it is a versatile herb that behaves as a short-lived perennial in warmer climates and an annual in cooler regions. There are two main types often found: Krishna Tulsi, which has dark purple-tinted leaves, and Rama Tulsi, which features bright green foliage.
The plant has a distinct, complex aroma that is often described as a blend of clove, mint, and lemon with a spicy, peppery finish. It grows into a small, bushy shrub reaching about 60 to 90 centimetres in height. Beyond its culinary use in Thai stir-fries and herbal teas, it is highly valued as a “queen of herbs” for its adaptogenic properties, helping the body manage stress. In the garden, its fragrant blooms are a magnet for bees and other beneficial pollinators.
Care Tips
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Position: Thrives in full sun. It requires at least 6 hours of direct sunlight daily to develop its essential oils and maintain its bushy habit.
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Climate: Loves heat and humidity. It is highly sensitive to frost and will usually die back if temperatures drop significantly. In temperate parts of Australia, it is best grown in the warmer months or kept in a pot to be moved into a greenhouse or indoors during winter.
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Soil: Prefers rich, loamy, and well-drained soil. If planting in the ground, enrich the soil with compost or well-rotted manure before planting.
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Watering: Requires regular watering to keep the soil consistently moist but not waterlogged. It is less drought-tolerant than standard Mediterranean basils and will wilt quickly if left to dry out completely.
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Fertilising: Apply a balanced liquid fertiliser every 2 to 4 weeks during the active growing season to support continuous leaf production.
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Pruning: Regular harvesting or “pinching out” of the growing tips is essential. This prevents the plant from becoming leggy and encourages it to grow into a dense, productive bush. Remove flower spikes as they appear if you want to focus the plant’s energy on leaf growth.
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Maintenance: Keep an eye out for aphids or whiteflies, which can occasionally target the soft new growth.
