Seven easy, natural pest-control recipes to debug your rainy season

August 29, 2014

As the tropical rains increase in the last quarter of the year, so do the bugs – and for the gardener, that can spell trouble.  Most gardeners these days are looking for safe products to use for the garden, so here is a collection of natural insect controls you might find useful, and can make right in your kitchen. Let’s start with one of my favorites.


1.5  tsp. of baking soda
1. 5 tsp. of natural liquid soap (or 1 tsp. of Bio Land glycerin soap)
1 tsp. of cooking oil
1 tsp. of vinegar
5 cups of warm water

Blend all ingredients together with the warm water, then use a hand-held spray bottle to mist plants until they are dripping wet. Also spray the walkways and areas around your plants.  This spray has two functions: It makes the leaves of the plants less palatable for the bugs, and it penetrates bugs’ exoskeletons, causing them to become sick.  Can be used weekly as preventive measure.


1 cup of brown sugar
1 cup of 3% hydrogen  peroxide
1 gallon water

This formula is effective as a plant enhancer and protector. Spray this mixture on your plants, and watch them turn dark green and shiny. The plants absorb the sugar solution into their leaves, while the hydrogen peroxide cleans the leaves of bacteria and fungus, creating healthy plants that bugs don’t like to eat. Some researchers speculate that the high levels of sugars in the leaf tissues may actually cause the bugs to become drunk from the fermentation of excess sugars into alcohol in their bodies.

It can be sprayed once a week as a preventive measure. The extra bonus this spray provides is tastier fruits and vegetables.


90 g chopped garlic cloves
2 tablespoons of cooking oil
15 g Bio Land’s glycerin soap
500 ml warm water.

Mix garlic and oil together and let steep for 48 hours. Dissolve grated soap in warm water and then mix the 2 solutions together; strain. Use 1 part mixture to 50 parts water. Spray as usual.

This organic pest control is useful against many insects and some caterpillars. It works best in the greenhouse or around the porch where the plants are protected from the rain.


2 hot chilies, chopped
2 large onions, chopped
1 bulb garlic, chopped
1 L Bio Land’s glycerin soap solution

This homemade insecticide and pesticide is very effective against any leaf-eating insects.  Best used in the greenhouse or porches where plants are protected from the rains.  Combine all the ingredients, including the seeds from the chilies. Cover with the soapy water and allow to steep for 24 hours. Strain. Add water to dilute if required and spray. Can be stored in a sealed container in the refrigerator for up to 2 weeks.


This organic control is effective against nematodes. Dissolve 2 kg sugar in a bucket of water. Drench the soil to kill nematodes. Molasses can also be used, but don’t use honey, as this may transmit disease back to the bees.


A agent for repelling ants and other types of pests, this mixture is very easy to prepare. Boil old coffee grounds in 1 liter of  water with 1 diced lemon along with some cinnamon. Strain the mixture and add some cayenne pepper. Spray the liquid under the leaves and on the roots to keep the pests away from plants.

You can usually ward off fire ants by pouring boiling water on their nests.  If several applications don’t work, try this recipe.  The orange or lemon rinds have an oil which dissolves the ant’s skin or exoskeleton. 


6-12 Orange or lemon rinds
125 ml  feed-grade molasses
4 liters of water

Boil the mix for 10 minutes, then apply to the ant nests.

Finally, remember that fertile soils are the key to healthy plants and people.  Healthy plants usually have fewer insect attacks, so fortify your soils with healthy organic fertilizers and use the above controls with moderation.  Until next time, enjoy your time in the garden.

For more information on tropical gardening – naturally – visit or contact Ed at 



You may be interested

5 questions for Costa Rican artist Adrián Gómez
Weekend Arts Spotlight
Weekend Arts Spotlight

5 questions for Costa Rican artist Adrián Gómez

Elizabeth Lang - March 17, 2018

Art that helps build a collective imagination depicting the vibrancy and liveliness of Costa Rica's Caribbean region: that's what characterizes…

Ramírez announces a National Team lineup with a few surprises
La Sele
La Sele

Ramírez announces a National Team lineup with a few surprises

AFP - March 16, 2018

Oscar Ramírez, coach of Costa Rica's Men's National Soccer Team, raised some eyebrows when he presented his lineup for two…

From New York to Costa Rica: ‘Costa Rica changed my entire life’
The World in Costa Rica
The World in Costa Rica

From New York to Costa Rica: ‘Costa Rica changed my entire life’

Elizabeth Lang - March 16, 2018

A one-time Costa Rican vacation. That was the initial idea of Andrea X, better known as Satya X – but…