By far one of the biggest obstacles of
successful organic farming in the tropics is insect pressure. In
fact, using the term pressure is not even accurate in that many times it
is all or nothing. In North America or Europe, usually you will
pest problems which may result in you losing a small percentage of your
crops. Be it tomato blight or cabbage moths or aphids, an
experienced gardener has probably seen all of them and lost some of
their crop each time. In fact, one of the hallmarks of a seasoned
gardener is how they deal with infestations and end or limit the
damage. Did the blight take 5% of your tomatoes? In the
tropics, the insects are much more aggressive and prolific. It is
not uncommon to have a gardener report ´all of my pepper plants
just vanished´ overnight.
For this reason, organic farming is even more
important in the tropics because with the traditional farms, you are
literally getting a mouthful of insecticides with each bite because the
farmers are so paranoid about being wiped out. To make matters
worse, because of the frequent rainfall, farmers are forced to reapply
the insecticides many times.
Fortunately the solution for organic farming is
pretty straight forward, it just requires being proactive and designing
your garden area with insect control in mind. There are generally
three things you can do. The first is Neem oil and other organic
sprays, the second is barrier plants and the third is inter-cropping.
Neem is a tree that grows quickly and
everywhere in Central America. There are many different ways to
use Neem as an insecticide but probably the easiest way is to simply
take a plastic barrel, fill it with Neem leaves, then fill it with water
and let it sit for a week. At the end of the week, just use a
sprayer to spray the water over all your plants and open ground.
Then fill the barrel again with leaves and water for next week.
The old Neem leaves will stink really bad and so we don´t even add them
to our compost pile, instead we put them on the outside of our security
wall against the bottom with the hopes that maybe they will deter
insects from going under the wall. Neem
trees are easy to find as seedlings and grow very rapidly or you can
just take a garbage bag and pillage a nearby tree on public land, nobody
will care if you strip off a few handfuls of leaves. There are Neem trees everywhere and most people don´t know about their insecticide properties.
There are a few other types of sprays which can be used that are free and easy to make, the most frequently used are garlic and mint. In the tropics, similar to many parts of the USA, mint grows like a weed. On our farm we use mint in a few different ways. The first is that we use it as a border for our egg-layers as well as beneath the actual hen coop. This is used to improve the smell and also to deter rodents. Mint is not a preferred food for the hens, so they generally leave it alone unless they are very hungry. For this reason we always have large amounts of mint available. Mint spray is made similar to Neem spray, simply fill up a container with leaves and allow it to soak for a few days and then spray around the garden. The strong mint smell distracts and confuses insects. Garlic spray is made the same way, simply soak it in water for a few days. We do not use garlic sprays often as garlic is a cash-crop while Neem and mint are basically free resources. Another free resource you can use is coffee grounds. Sprinkling coffee grounds around susceptible plants can deter some pests. We do not have free supply of used coffee grounds so seldom use them in this way. (Anyone want to set up a Starbuck´s franchise next door?). Despite conventional wisdom, coffee grounds do not make your soil more acidic. Most of the acidity is removed from the coffee grounds when they are used to make coffee.
Our second method for dealing with insect
pressure is barrier plants. Our garden is set up with 8 cages ( 6m
x 10m) in which we grow our vegetables. Around the outside of
each of our cages is a 1 meter wide bed that contains plants designed to
repeal or confuse pest insects. This moat around each cage
contains Marigolds, Nasturtium, Garlic and many different types of herbs
including mints, oregano, basil and many other typical kitchen
herbs. The area around the cages gives us space to grow herbs and
garlic, with the added benefit that they help protect the vegetables
growing inside the cages. I have seen suggestions that a good 20%
of your vegetable garden should actually be flowers. Not only do
herbs and flowers confuse pests, but they attract other useful insects
that either aid with pollination or else eat the pest insects. The
two most famous being ladybugs and hover wasps. If you allow farm
tours or your garden is visible from the street, this will also greatly improve the visualization and marketing of your vegetables. As a garden full of herbs, flowers and butterflies contrasts completely with a farm of barren dirt being sprayed continuously from a dust-cropper.
Another piece of the solution for insects in
the tropics is how we arrange the vegetables inside the cages. One
of the most important things you should not do while planting in the
tropics is plant in rows or even patches. Many pest insects have a
favored food and by planting them in a row, it is like setting up a
buffet line for the insects. Instead, confuse the insects by
inter-cropping. We use a modified version of Square Foot Gardening
called Arms Reach Gardening which allows us to easily design our garden
to have, for instance, our cabbage plants spread out throughout the
cage rather than all in a straight line. It also allows us to
design to have onions protecting certain plants instead of having them
just in a straight line and not being very effective as an insect
By planting flowers as barriers throughout your garden and by inter-cropping
your vegetables you will do a lot to slow down any pest damage which then can be managed manually.
Weekly applications of Neem or mint water is a quick and free solution
which you can use proactively or wait until you detect a problem.
There are other things you can do which are, in my opinion, borderline
organic. Boric Acid ( Borax) is a powder you can buy very
cheaply at many pharmacies or hardware stores. Mix it 50-50 with table sugar and then
add enough water to make it fluid. Put a tablespoon of the wet
mixture on a little piece of cardboard and spread the cardboard pieces
throughout your garden. This will put a
huge dent in the ant population and at least make them manageable for
your first year. Boric a cid is technically considered organic so
no harm done, however, some may moral issues dropping tablespoons of
acid around their garden.