Neem!

Neem trees (center) growing within a Kona coffee orchard for shade, insecticidal properties, timber, and medicine.

It’s great that so many people are jumping on the homegrown food bandwagon. There is nothing more delicious and healthful than your own fresh fruit and vegetables grown with love without pesticides, herbicides or chemical fertilizers.

But for me, homegrown also means making my own medicines from plants in my garden, from the wild and from friends’ yards. And also using locally sourced materials -- like neem -- to improve soil fertility and food production. Recently I was brought into a discussion about a number of neem trees growing on the Hamakua Coast. The property owner had wanted to tear out his 70 or so trees in favor of fruit such as lychee and longan. Although I wasn’t directly involved in convincing him of their value, I am very happy that this valuable resource is now being preserved.

Neem, or Azadirachta indica, is native to India and Burma and has been used in Ayurvedic medicine for 5,000 years — the leaf is included in 75 percent of their treatments, and they use other parts of the tree as well. It treats a variety of human health problems, from skin rashes to diabetes.

It’s also useful in helping to deter or kill destructive insects. The Colorado State University Web site states, “Neem seed contains materials that disrupt insect growth and is useful for control on developing whiteflies and some other insects.” Neem, in the form of oil or cake, is also used extensively in India and on many organic farms as both a pesticide and fertilizer.

A number of us gathered at my garden near Keaau on Sunday, May 15, to learn more about this wonder tree and its many uses. I gathered a bunch of small branches with lots of leaves from a friend’s property nearby and we brewed some of them into a strong tea to be used either as an insect spray or a poultice for skin problems. I had made an herbal oil before the workshop with fresh neem leaves and olive oil, which we strained and combined with a bit of beeswax and various essential oils for a nice skin healing salve, which turned out great and it a joy to use. My precancerous skin keratoses already seem better.

Another use that one of the workshop participants reported was the use of ground-up neem trees, including bark, branches and leaves, as a mulch around plants normally affected by Chinese rose beetles: the results have been encouraging, with far less damage to susceptible plants than before the mulch was applied.

How does neem work? When insects contact neem seed oil and other forms of this tree, it blocks the effects of their hormones, which causes them to stop mating, eating and reproducing. They eventually die, causing the population in your garden to decrease. Unlike conventional insecticides that kill quickly, the effects of neem oil take longer, several days. Neem affects only chewing and sucking insects: direct contact affects  insects that suck the juices out of plants, such as aphids, scale and those that chew the leaves and other parts of plants, such as grasshoppers. It does not affect ladybugs, honeybees and other beneficial insects that prey on the bad insects unless you spray them directly. And if you eat a sprayed plant, it will not harm humans. The Environmental Protection Agency says neem is Generally Recognized As Safe (GRAS) for use on food products.

If we learn to make our own plant medicines, insecticides and other locally available products that we would otherwise purchase, it will only serve to make us more self-sufficient and will expand our capabilities as homegrown enthusiasts.

Pahoa Feed and Seed is selling young neem trees, so if you want a great medicinal plant and one that you can use for fertilizer and to help repel certain insects, neem is a tree that seems to grow well in windward locations on the Big Island. Kona side residents who are growing neem — please let us know of your success! Cold Extracted Neem oil is available at several farm supply stores, and is also marketed by Sam’s Original Organic in Honaunau.

Here is a list of herbal preparations you can make from neem and just about any other herb:

To see a short video of the Neem Workshop, click here.

Sources and Additional Information: