Sweet basil (Ocimum basilicum) is the common culinary herb known to most but there is much more to the world of basil than this one aromatic herb. There are dozens of different cultivars – annual and perennial – with varying leaf sizes and colours and diverse flavours that can be used for cooking, medicinal purposes and repelling pests.
The essential oils found in basil give rise to its medicinal uses. Basil tea is common in traditional medicine as a tonic and to help with indigestion and loss of appetite.
As a pest repellent, basil is helpful to plants and humans. In Asia, the crushed fresh leaves of holy basil are rubbed onto the skin to repel mosquitoes, while any of the basils grown in pots near doorways and windows will help keep flies away. Made into a spray, basil will repel a range of problem insects including aphids, thrips and whitefly. To make, pour 1 litre of boiling water over 2 cups of firmly packed chopped basil leaves. Cover and leave to stand until cold. Strain and use within a few days.
There are a wealth of different basils out there. Here's a handy guide to some of them:
- Sweet basil (O. basilicum): glossy green leaves and grows about 50cm high with tapering spikes of white flowers. There are numerous cultivars including:
- ‘Genovese’ and ‘Sweet Italian’: typical tender lime- green leaves with a delicious clove flavour.
- ‘Cinnamon’ basil: sweet cinnamon and clove scented leaves with purple flowers and bracts.
- ‘Crispum’ lettuce-leaf basil: large crinkled leaves.
- Purple basil ‘Purpurascens’, ‘Dark Opal’ and ‘Purple Ruffles’: all have deeply purple leaves with a milder clove flavour.
- Thai or liquorice basil ‘Siam Queen’ and ‘Thai’: deep green leaves with purple stems, mauve flowers and purple bracts. The scent and flavour is strongly aniseed and clove.
Other annual basils
- Dwarf basil (O. minimum) with cultivars ‘Greek Mini’, ‘Fino Verde’ and ‘Spicy Globe’: small-growing bushes with small clove-scented leaves. Good for pots or as a low hedge.
- Hoary basil (O. americanum): long leaves and an interesting camphor and clove scent.
- Lemon and lime basil (O. x africanum – previously called O. x citriodorum): grows as a delicate shrub with slender leaves and a strong lime or lemon flavour.
- Clove or African basil (O. gratissimum): grows large to 2m high with lime green leaves and pale yellow flowers. The whole plant smells sweetly of cloves. There is also a partially red-leafed form.
- Green pepper basil (O. carnosum syn. O. selloi): glossy green leaves with dark stems and spikes of pale mauve or white flowers, and a spicy green pepper flavour. Rare in Australia but likely to become more common.
- Holy or sacred basil (O. tenuiflorum): medium- sized bush with softly hairy leaves. Also known as tulsi, it is used in religious ceremonies and medicinally in much of Asia but is less likely to be used in cooking.
For the full story on basil, including planting times and growing conditions, companion planting and pests and diseases, grab the October 2016 (Issue 90) of ABC Organic Gardener OUT NOW!
By: Penny Woodward
First published: November 2016