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!
Palmarosa Essential Oil
Palmarosa Essential Oil (Cymbopogon martini) is one of the lemongrass varieties native to India and Indochina. Palmarosa Essential Oil is steam-distilled from its slender, aromatic leaves, and with its soft, floral fragrance with hints of citrus, this essential oil is prized for both its soothing aroma and remarkable skin-supportive properties.
In the Garden
Research on the essential oil of Palmarosa showed it is effective as a biopesticide used alone or alongside other agents against diverse targets, including agricultural and stored grain pests, fungi, viruses, household pests, and blood-feeding insects.
Cymbopogon Essentail Oil is a complex blend of bioactive compounds, mainly composed of monoterpenoids, sesquiterpenoids, and phenolics. Citral, geraniol, citronellal, and limonene are key constituents that impart its distinctive aroma and therapeutic properties
It is a potent, eco-friendly Fumigant, Repellent, and Antifeedant. It also offers effective control of Fungi and Viruses.
Mosquitoes
Mosquitoes rely on highly specialized olfactory receptors to detect environmental cues like carbon dioxide, body heat, and human skin odours. These receptors are located on their antennae, maxillary palps, and proboscis, and play a crucial role in host-seeking behaviour and the transmission of diseases like malaria and dengue fever. Palmarosa essential oil disrupts their olfactory receptors, serving as a highly effective, natural insect repellent, providing up to 100% protection against major mosquito species.
Ticks & Fleas
One of veterinary medicine’s ongoing challenges is controlling ectoparasites in companion animals, which has considerable implications for both public health and animal care. Fleas and ticks are not just nuisance pests but also serve as vectors for numerous zoonotic infections, making their efficient control a crucial component of preventive veterinary care.
Flies & Gnats
The strong aroma of Palmarose essential oil functions as a spatial deterrent, clearing immediate areas of flies and minor crawling insects.
Moths & Caterpillars
Palmrosa essential oil exhibits strong antifeedant and contact toxicity against foliage-eating larvae, making it viable for crop protection.
African Bollworm, Cotton Bollworm (Helicoverpa armigera)
The African Bollworm is a highly destructive agricultural pest in South Africa. It attacks a wide range of commercially important crops, including maize, cotton, soybeans, tomatoes, and deciduous fruit, including blueberries and raspberries.
The life cycle of Helicoverpa armigera consists of four distinct stages: egg, larva (caterpillar), pupa, and adult (moth). In South Africa’s warm climate, the entire cycle can be completed in as little as 4 to 6 weeks, allowing for up to 5 generations per year.
Female moths lay hundreds of eggs singly on young leaves, flowers, buds, or developing fruit. The Caterpillars moult through 6 distinct growth stages (instars).
This is the only destructive stage. Young larvae graze on leaves, while older larvae bore deep into fruit and stems.
The caterpillars vary in colour from yellowish to dark green or almost black, but are typically characterized by a spotted appearance with small bumps and a light longitudinal stripe running down each side of the body.
The Pupal Stage last 10-14 days, and mature larvae drop from the plant and burrow 3-10cm deep into the soil. The pupae enter a resting state (diapause) in the soil to survive the winter.
Semi-loopers
The Plusia Semi-looper (Thysanoplusia orichalcea) and the Tomato Semi-looper (Chrysodeixis acuta) are moths whose larvae are common leaf-eating caterpillar pests in South Africa, feeding on the foliage and fruit of crops like Tomatoes, Potatoes, Soybeans, Barley, Linseed, Sorghum, Bananas and Cotton.
The Lesser Armyworm, Beet Armyworm (Spodoptera exigua) is a moth whose larvae are a destructive agricultural pest. In South Africa, it attacks broad-leaf vegetables like Spinach, Beetroot, Peas, and Grains, Cotton and Tobacco. The caterpillar’s damage crops by skeletonizing leaves, spinning webbing, and boring into growth points.
Stored-Grain Protection
Palmarosa essential oil is a potent, eco-friendly botanical pesticide. Rich in geraniol, it acts as a highly effective Fumigant, Repellent, and Antifeedant against agricultural, household, and stored-grain pests without harming seed germination or leaving toxic chemical residues.
Research has shown that due to the limonene and linalool components of Cymbopogon, as a fumigant it is effective at repelling and causing mortality in stored-product beetles like the Red Flour Beetle and the Saw-toothed Grain Beetle without affecting crop viability.
Fumigation
The essential oil can be introduced to sealed storage containers to deter pests and affect adult development without impacting the germination rate of legumes or cereal.
Protection
Add a few drops of pure oil to porous clay pucks or sachets and place them inside sealed storage containers. The released fumes safely repel beetles without diminishing seed viability or germination rates.
Pulse Beetles (Callosobruchus species)
The term “pulse beetle” is a common name used to refer to a few closely related species of seed beetles that are major pests of stored legumes in South Africa.
Adzuki Bean Weevil, Chinese Bruchid (Callosobruchus chinensis)
In South Africa the Chinese or Adzuki Bean Bruchid, is an invasive pest of pulses like stored legumes, resulting in severe damage to chickpea, lentil, mung bean, and cowpea crops by eating the seeds from the inside out.
Cowpea Weevil (Callosobruchus maculatus)
The cowpea weevils are a major agricultural pest of stored pulses, including cowpeas and bambara groundnuts in South Africa. The insects begin infesting crops in the field before laying eggs directly on dry, stored beans, which can lead to significant post-harvest losses.
Saw-toothed Grain Beetle (Oryzaephilus surinamensis)
This cosmopolitan stored-product pest is distributed across more than 100 countries globally. In South Africa, the beetle frequently occurs in pantries, warehouses, mills, and food processing facilities. It thrives in dry, warm environments and attacks a wide variety of dried foodstuffs, including cereals and grains, dried fruits, rice, oilseeds and nuts.
Garden Spray
Palmarosa Essential Oil contains natural properties that act as a deterrent for common garden insects. Here is a straightforward, non-toxic recipe to keep your plants bug-free.
Mix 10-20 drops of the essential oil in 1 Litre of water with an emulsifier. Shake well, and regularly while spraying down the foliage of plants.
The Cotton Wool Method listed below is also effective.
In the Home
Palmarosa essential oil is prized for both its soothing aroma and remarkable skin-supportive properties. Known as a natural hydrator, Palmarosa Essential Oil helps lock in moisture, making it a favourite in skincare routines.
Its antiseptic and cicatrizant properties support healthy skin by promoting healing and reducing the appearance of scars. Palmarosa also aids digestion, calms the nervous system, and can help restore emotional balance.
The pale yellow to light green oil is steam-distilled from the grassy leaves and is thin with a sweet and rosy floral scent with a hint of citrus.
To repel pests across entire rooms or patios:
Combine 3 drops of Palmarosa, 2 drops of Citronella, and 2 drops of Lemongrass essential oil. Add the mixture to an active water diffuser or a room mist bottle filled with water to clear ambient spaces of flying insects.
Diffusing essential oils will deter many common indoor pests
- 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 bath 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.
