Chris of Sanur writes: Where can I find young Neem trees, and what plants can I use in my garden to control mosquitoes?
I little realized when I began researching this article, what a wealth of very interesting information I would find. The Neem Tree (bot: Azadirachta indica) is a truly amazing tree which has been in use for many medicinal purposes for at least 5,000 years; most significant to Ayurvedic medicine. In some way as yet undiscovered, it alters the mosquito’s hormonal balance which prevents it from actually laying its eggs. This, and other interesting material, will be the subject of my next article.
The short answer to the first part of your question is to seek out the organic markets regularly publicized in the B.A. calendar. I would start with the Sunday market in Ubud. If young trees are not available just now, Neem oil almost certainly will be. Place an order for your trees and buy some oil for use in the meantime.
Mosquito control is a constant battle of attrition! While you may do all you can in your own garden, there is little you can do (short of screening the entire area) to prevent mosquitoes coming in from outside in search of warm mammalian blood. If you live within flight of sawah in its wet stage, your problems are magnified. This can be over quite some distance, depending on prevailing breezes.
Plants which have known mosquito repellent properties are lemon grass; basil - all kinds, but Italian sweet basil is the best; the South African pyrethrum daisy (not sure if it is available here but seeds should be relatively easy to obtain); and of course the Neem tree.
It is the essential oil of these plants which is most effective, either to rub onto the skin or to vaporize by means of an aromatherapy burner. I have seen these for sale here. They may be activated by a tea-light candle or swish models incorporate a tiny electrical heater. It is these volatile oils which are most effective. At close to 100% pure, they are very strong and should be much diluted with a carrier oil (coconut/peanut etc.) if they are to be applied to the skin. A few drops in water is sufficient for a burner.
Lemon grass oil (known as Oil of Citronella in the West) has long been an effective repellent. An Austrian friend of mine who comes to Bali regularly and whose blood mozzies seem to find irresistible, usually brings repellents with her. She has found lemon grass oil to be by far the most effective; often out-performing preparations containing DEET.
I would make large plantings of all four in my garden with particular emphasis on the outdoor areas where I prefer to sit. To some extent, the volatiles may be released by disturbance of the leaves. (Ever noticed how strong the scent of such plants seems after a shower of rain?) The same effect can be had by ‘tickling’ (not beating) the leaves every now and again with a thin bamboo rod.
Make a point of collecting any fallen leaves, twigs, bark, of these plants to burn in a small brazier. Cut some green leaves so that they smolder rather than burn quickly.
Garden hygiene is also important! Mozzies can breed in a surprisingly small amount of still water. Saucers under pot plants should be regularly emptied as this is a No:1 breeding site. Ornamental pounds must be stocked with hungry fish. It is often said that a hungry fish is a healthy fish and mosquito wrigglers are a favorite food.
Do not allow your pond to become too overgrown – there should be at least 30% of the water free of surface plants – remember that the submerged oxygenating plants need some sunlight to grow and prosper as do the fish. Don’t throw away the discards – use them on garden beds as mulch. Encourage insect eaters such as cecak (geckos); the mozzies they consume more than make up for cleaning up their droppings.
Regularly patrol your garden for breeding sites. Any places where water can lie for more than 24 hours should be drained or otherwise dried up; cans, plastic bottles, old tyres; should be gathered up and disposed of.
If all else fails, consider permanently enclosing your favorite sitting area (eg: terrace/porch) with mesh. Lightweight sliding panels in the Japanese style need not be expensive. If you use black nylon mosquito screening, the eye/visual cortex soon learns to ignore these and to all intents and purposes they become invisible.
Above all, plant as many Neem trees around your garden as you can comfortably accommodate. As they grow and prosper, they should take over the job and render most of the above measures (but not the removal of breeding places) un-necessary.
Please send all your gardening questions to
E-mail: gardendoctor08@yahoo.com
