Description
Essential Oils for the Home & Garden
If you are trying to limit your exposure to toxic and synthetic chemicals in your garden and home essential oils can be valuable tools. They are well-known for their wellness virtues for humans, and can also be precious allies to protect your plants naturally and ecologically.
These oils have been used for thousands of years for their medicinal and cosmetic benefits, and their power lies in the hundreds of chemical constituents they contain. Whether you are trying to chase away garden pests from your vegetable or flower garden, protect your plants against diseases, or simply to improve their overall health, we can use these natural defences to our advantage in both our home and garden, using products you can store in your medicine chest. How cool is that!
Aniseed Essential Oil
Aniseed (Pimpinella anisum) is native to the eastern Mediterranean and Southwest Asia, and our essential oil is carefully steam-distilled from sustainably grown anise seeds.
In the Garden
Among the numerous biological properties exerted by aniseed essential oil, are its antimicrobial and antifungal effects on plants.
Thanks to its active compound trans-anethole and p-anisaldehyde, aniseed essential oil serves as an eco-friendly bio-pesticide, and a natural deterrent for certain pests.
It is also toxic and repelling to a variety of agricultural and stored-product pests, safely acting as a natural pest control without introducing synthetic chemicals harmful to the environment.
Besides the pests mentioned below, Aniseed Essential Oil also repels Spider Mites, Nematodes, and Cabbage Worms.
Essential oils from both Aniseed and Fennel are the dominant ones that are effective as repellents and insecticides against several insect pests, and are safe for non-target organisms, humans, and other animals.
Aniseed essential oil is utilized across agriculture (crop protection) and veterinary medicine (pet and livestock care) to manage parasites and prevent the spread of diseases.
Research on aniseed essential oil didn’t appear to harm the beneficial invertebrates like Beetles and Worms that were also studied.
Because of its strong, sweet aroma Aniseed Essential Oil is highly effective at attracting bees. Gardeners and beekeepers often use it to lightly scent swarm traps, hives, or sugar water to encourage colonization and pollination in their organic gardens.
Ticks and Mites
Its acaricidal effects have been extensively investigated for the formulation of bio-pesticides against larvae and adults of various pests and vectors. An acaricide is a type of pesticide specifically designed to kill or control members of the arachnid subclass Acari, which includes ticks and mites, and aniseed essential oil has proven its insecticidal and acaricidal (tick/mite) properties.
Red Flour Beetles & Confused Flour Beetles
Studies done on Red Flour Beetles (Tribolium castaneum), which are some of the most destructive pests of stored whole and ground grain around the world, looked at how the essential oil can be used to repel these beetles. Another study found it to be highly effective against Confused Flour Beetles (Tribolium confusum).
Mosquitos
Researchers also looked at repelling Southern House Mosquitos (Culex quinquefasciatus) a highly common, cosmopolitan species frequently found across South Africa. It was found that the essential oil was toxic against this pest in all stages of life except for the eggs. Aniseed repellents are currently patented for using aniseed oil to get rid of Mosquitos.
Green Peach Aphids/Peach-Potato Aphid
Aniseed essential oil was also found to be effective against Green Peach Aphids/Peach-Potato Aphid (Myzus persicae). This very widespread and destructive agricultural pest is found on a wide variety of crops and garden plants across South Africa.
The aphids are polyphagous, meaning they feed on over 40 different plant families. In South Africa, they are frequently found on Solanaceae crops like Potatoes and Chillies, Brassicas like Cabbage, Canola, and Tobacco. Because our winters are so mild, they usually do not even need to lay eggs to survive the cold. Instead, they reproduce asexually, giving birth to live young all year round.
Beyond the physical damage caused from these sap-sucking insects, they are notorious vectors for spreading plant viruses, such as the Potato Leafroll Virus (PLRV) and the Potato Virus Y (PVY). These little critters are carefully monitored in commercial farming by the South African Potato Industry, and are often managed using biological controls (like parasitic wasps) or chemical agents.
Tobacco Cutworms/African Cotton Leafworm
Aniseed essential oil was also found to be most effective against Tobacco Cutworms (Spodoptera littoralis), commonly known as the African Cotton Leafworm or Egyptian Cotton Leafworm, a highly destructive polyphagous pest that feeds on a wide range of commercially important crops in South Africa, including Maize, Cotton, and Grapes.
Green Peach Aphids & Pea Aphids
Another study looked at aniseed oil when used to target Green Peach Aphids and Pea Aphids (Acyrthosiphon pisum) a cosmopolitan species that is widespread across South Africa and the African continent.
The Pea Aphid is a well-known agricultural pest. In South Africa, it is known to colonize crops like Field Peas (Pisum sativum) and Alfalfa. The University of the Free State has documented specific local strains of the pea aphid in the country and has evaluated their survival, reproduction, and potential to cause agricultural damage on local field pea genotypes. Because of its broad global distribution and its role as a vector for various plant viruses, it is monitored in agricultural regions alongside other aphid species. Once again, research showed that Aniseed Essential Oil was highly effective, killing 95% of Green Peach Aphis and 87% of Pea Aphids.
DIY Garden Spray:
Mix 10-20 drops of the essential oil, and 1 teaspoon of mild liquid soap, with 1 Litre of water.
In the Home
Aniseed oil is known for its sweet, liquorice-like scent with a hint of spice, and has been used for centuries in cooking, traditional medicine, and perfumery.
With its crisp, stimulating aroma, aniseed essential oil is often used in wellness blends to promote digestive comfort, clear breathing, and mental clarity.
Its thin consistency and middle note character make it a vibrant addition to massage oils, vapour rubs, and oral care formulations. It adds a middle note of warmth and complexity to aromatherapy blends.
- Add a few drops to a diffuser to create a peaceful, meditative atmosphere.
- Dilute with carrier oil for use in massages or skincare applications.
- Combine with Epsom salts and other relaxing oils for a deeply calming soak.
How to Use Essential Oils for Pest Control
When it comes to organic gardening, prevention is better than cure, and spraying crops regularly with essential oils to prevent insect infestation and disease is the most effective method. This will not only chase pests away, but also make your garden smell great!
Always use pure essential oils, and because they are so potent, always dilute them first.
How to dilute essential oils
One of the drawbacks of using essential oils in the garden is that the levels of terpenes and other constituents can vary greatly depending on the region where the plants are grown, genetics, climate and other seasonal factors. Therefore, maintaining consistency in the chemical profile of the oils is hard.
For example, Rosemary oil extracted from plants growing in two different regions of Italy will contain varying levels of α-pinene, ranging from 11% to 36%. Another study showed that essential oils extracted from different chemotypes of garden thyme did not have the same toxicity against the bean weevil.
This is the reason why, if you look for exact recipes for the oil you wish to use in the garden, you will find many different quantities of oil versus water used.
Another factor to take into account is the actual number of drops in a milliliter can vary greatly depending on the thickness of the liquid: Thicker liquids like essential oils produce larger drops, meaning it takes fewer drops to make 1mL. Different dropper bottles or droppers also have varying nozzle sizes, which changes the volume of a single drop.
In standard pharmaceutical measurements, 1 mL is equal to approximately 20 drops (meaning 1 drop is about 0.05 mL). Therefore, 10 drops are typically equal to about 0.5 mL.
This is why physicians do not rely on counting drops, as this can lead to incorrect dosing. Instead they use an oral syringe, a graduated measuring cup, or the specific dropper provided with the medicine.
CAUTION:
Because the actual number of drops in a millilitre can vary greatly depending on the thickness of the liquid and varying nozzle sizes, which changes the volume of a single drop, I recommend starting with the lowest recommended dosage. You can always increase it later.
Preventative Spraying
A general guideline when mixing sprays to deter insects, and for anti-fungus protection is to mix 4–8 drops of Essential Oil in 1 Litre of water with an emulsifier.
Garden Sprays
At certain times of the year various pests and diseases will be more prevalent, so for stronger protection dosages can be increased.
Generally you will find recommended dosages are between 10-20 drops per Litre of water.
Always Test Sprays First
Unless you apply very high doses of essential oils, they are perfectly safe to use in the garden. However, because the strengths of essential oils vary, to ensure they do not cause leaf burn, it’s important to always test your spray on a small, isolated area of the plant first. Wait at least 24 hours to check for damage before applying it everywhere.
A good method of remembering which leaves you tested your spray on is to tie string or ribbon onto the stems that have been sprayed.
Take Notes
Taking note of which plants were tested and the dosages used, will soon give you a good indication of the strengths your plants need for protection.
Mixing your spray
The Emulsifier:
Soap is essential as an emulsifier as essential oils do not mix with water and will float to the top, potentially burning your plants. A gentle liquid dish soap, pure liquid Castile or Black soap can be used.
Approximately one teaspoon of liquid soap emulsifier is used in one litre of water. Witch hazel, Vodka, or apple cider vinegar also emulsifies oil and water.
The Method:
In a small glass container, mix your essential oils with your emulsifier, then add some of the water and stir well. Warming the water helps with emulsification. Add the oil mix to the spray bottle with the rest of the warm water. Agitate well and also regularly whilst spraying.
Applying your Oils
Spraying in the middle of a hot, sunny day can cause leaf burn, so always apply the mixture in the cool of early morning or late afternoon. Remember to agitate the spray bottle well before use, and regularly while spraying. Ensure that you spray underneath the leaves where insects commonly hide.
During the cooler times of the day beneficial daytime pollinators are not that active. Never spray plants if you can see beneficial pollinators like bees around the plants. Even organic sprays can be abused in the garden, so as they say “everything in moderation”.
NOTE: The strength of the oils will evaporate, so reapply to plants after rain, every 2 weeks, or as needed.
Cotton Ball Method
To target specific insects in large numbers, like ant hills or rodent burrows, take some cotton balls and add a few drops of essential oils to them. Place the cotton ball right onto the ant hill, burrow or other insect grouping. This will cause them to relocate immediately. If that doesn’t work immediately you should repeat the process using a stronger solution.
You can also rub the oils onto any hard surfaces to create a long-lasting barrier.
Hanging Strips to Deter Pests
Add essential oils to a bowl of warm water and soak strips of pretty material or ribbon in the water before hanging onto the branches of fruit trees, or near edible gardens and ornamental shrubs.
Is there a waiting period before harvesting?
You should not eat vegetables and fruits immediately after spraying them with essential oils. These oils are highly concentrated and consuming them without a waiting period or proper cleaning can cause digestive upset, inflammation, or irritation of the mouth and oesophagus.
Essential oils degrade in sunlight and waiting 24 hours should be sufficient. Ensure that you always wash your food well and all will be fine.
Storing Essential Oil Mixes
Try to mix up only sufficient spray to use in a day, or within 24 hours of mixing. Once exposed to water and oxygen, oil-based garden sprays begin to separate, degrade, and lose their effectiveness.
If you do have any left-over, store it in a glass bottle in a cool, dark place, not in your plastic spray bottle, as essential oils break down quicker in plastic. Agitate well before using again.
