Potted Science: Basil
In the first online part of this exclusive series for The Greatest Minds, former research scientist M. N. Jones takes a look at some of the hidden science behind our favourite potted plants; but whether you are a chef, gardener or just vaguely curious, the Biological Secrets of Basil (Ocimum basilicum) might surprise you.
Although it is mostly closely associated with Italian cooking, the basil plant, Ocimum basilicum, was originally native to India and the Middle East. It has now become naturalised in some areas of Africa and is cultivated widely elsewhere. As a member of the Labiatae or Lamiaceae (mint) family, basil is related to a number of herbs, including garden familiars like majoram, rosemary, sage and savory; it is also related to the teak tree. Basil is often described as a half-hardy annual garden plant, but it really comes into its own as windowsill potted plant- not least since it needs a minimum night temperature of around 12 or 13⁰C.
In recent years there has been an explosion of scientific interest in the chemicals produced by plants and in the potential health benefits of herbs and the substances they produced. Antioxidants are also very much in vogue, so it is perhaps not surprising that basil, in common with many other herbs, has been tested for antioxidant properties. In the case of basil, a joint Korean, Japanese and American team published a study of its antioxidant properties back in 2004. Initially, the team identified the aroma-producing chemicals found basil leaves, then they set about testing their antioxidant properties. They discovered that a number of the substances produced by the plant had antioxidant properties, but a substance called Eugenol was particularly impressive in this regard.
Perhaps one of the stranger potential uses of basil is as a bioremediation agent to remove chromium from contaminated soil. Poisonous heavy metals like chromium are known to bind naturally to large sugar molecules (polysaccharides) and basil seeds are surrounded by an outer layer of just such a sugar- a polysaccharide called “pectin”. Consequently, it has been suggested that basil seeds could be used to remove chromium or other heavy metals from the soil. The fact that basil seeds are fairly cheap and abundant in many parts of the world is an extra bonus.
The Greatest Minds’ Top Tips:
Basil can be grown from seed; supermarket-grown basil sold as live plants is prepared to peak at the time of sale, so often dies without immediate nurturing, however, with the right care, these plants can be excellent and long-lived potted plants. If buying a supermarket plant, fertilize and water it upon returning home. Solid, slow-release fertilizer sticks designed for house potted plants are ideal for this. The plant may also be pot-bound and need to be re-potted.
Potted Basil thrives on warm, sunny windowsills, but requires frequent- often daily- watering when grown under these conditions. Ensure good drainage.
Regular trimming of the shoots and some of the leaves (whether or not they are to be eaten) stimulates basil plant growth and encourages the plant to develop an attractive, bushy, shape.
More on Growing Basil:
“Growing Herbs: Design, Planting, Harvesting, Using: an Illustrated Encyclopedia and Practical Gardening Guide”, Jessica Houdret, Pub: Southwater, London, , 2003, pages 188-189,
“Grow Herbs: an Inspiring Guide to Growing and Using Herbs”, Jekka McVicar, Pub: Dorling Kindersley Ltd, London, 2010, ISBN: 978-1-405356-6-7, pages 160-161, also pages 162-163 for “Eastern Basil” (several Ocimum species and hybrids such as “Thai Basil”, “Lemon Basil” and so on),
“Alan Titchmarsh- How to Garden- Vegetables and Herbs”, Pub: BBC Books, London, 2009, ISBN: 978-1-84-6073960, page 119.
Less Potted, More Science:
“Identification of volatile compounds in Basil (Ocimum basilicum) and Thyme leaves (Thymus vulgaris) and their antioxidant properties”, Seung-oo Lee, Katumi Umano, Takayuki Shibamoto and Kwang-Geun Lee, Food Chemistry, Vol. 91, Issue 1, 2005, pages 131-137,
“Removal of chromium by mucilaginous seeds of Ocimum basilicum”, J. S. Melo and S. F. D’Souza, Bioresources Technology, Vol. 92, Issue 2, 2004, pages 151-155.
Information in this column is provided for interest only. Plant-based remedies can be harmful as well as/instead of beneficial- contact a qualified medical doctor or pharmacist for professional advice before taking any such remedies. The author, editor and publisher take no responsibility for any problems caused by consumption of the plants discussed.
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