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!
Lavender Essential Oil
Steam distilled from the delicate purple flowers of Lavandula angustifolia, our essential oil is grown and sustainably harvested from lavender fields in the Mediterranean region.
In the Garden
Research has shown that the essential oils of Lavandula angustifolia demonstrate strong Antibacterial, Antifungal, Insecticidal, Repellent, and Herbicidal activities, making it a powerful, eco-friendly biopesticide and antifungal agent, and a promising natural alternative in plant protection.
Its active compounds, primarily linalool and linalyl acetate, damage the nervous systems of insects, disrupt fungal cellular structures, and act as strong, natural deterrents. Another active compound, borneol, is a naturally occurring bicyclic terpene and alcohol with a sharp, minty, camphor-like scent that confuses insects and repels Mosquitoes, Flies, Fleas, and Moths.
Moths, Fleas, Flies and Mosquitoes
For centuries, the lilac-coloured flowers of lavender have been used to add a sweet and pleasant fragrance to homes and clothing drawers. And while the vast majority of humans love the smell of lavender, mosquitoes, flies, ticks and other unwanted insects hate it
To repel insects, the compounds in fresh and dried lavender flowers, and the essential oil, are not the same. Studies have shown that the oil is much more potent, and a 20% solution of lavender essential oil in water or an unscented lotion can repel mosquitoes for up to 8 hours.
As a Contact Insecticide
Lavandula angustifolia acts as a botanical contact insecticide, primarily due to naturally occurring terpenoids like linalool and linalyl acetate. When applied directly to soft-bodied pests, the oil attacks the insect’s nervous system and acts as an anti-feedant, interfering with essential enzymes to cause knockdown and mortality. The oil can also act as a suffocant, physically interfering with the insect’s respiratory spiracles.
Contact sprays are primarily effective against soft-bodied insects and pantry pests, including: Aphids, Whiteflies, Spider Mites, Pantry Moths like the Indian Meal Moth larvae, and Weevils like the Lesser Grain Borer.
Research on lavenders biopesticidal activities indicates strong ovicidal, larvicidal, and repellent properties, making it an excellent natural alternative to synthetic chemicals.
Fungal Control
Lavender essential oil strongly inhibits fungal growth, germ tube formation, and hyphal elongation. It has been shown to be effective against common mould fungi like Candida in humans and various species of Fusarium in plants.
Fusarium
Fusarium Wilt
The genus Fusarium comprises a large group of fungi responsible for several diseases, depending on the host plant. The most prominent condition in plants is Fusarium Wilt caused primarily by Fusarium oxysporum. It blocks the water-conducting tissues (xylem), leading to yellowing, wilting, and plant death. Fusarium Wilt affects a wide variety of crops including Tomatoes, Bananas, Cotton, and Chickpeas.
Fusarium Head Blight/Scab
Fusarium graminearum is widely prevalent in South Africa and is a major pathogen for cereal crops like Maize, Wheat, and Barley. It is the primary cause of Fusarium Head Blight, or Scab, in Wheat and Barley, causing major concerns for crop yield and grain quality.
Maize Ear and Stalk Rot
Gibberella Ear and Stalk Rot, also known as Red Ear Rot is one of the major and increasingly recurring maize ear rots in South Africa, caused by the Fusarium graminearum species complex.
Fusarium Patch on Cool Season Grasses
Fusarium Patch, also known as Microdochium Patch or Pink Snow Mould primarily affects heavily maintained, close-mown, or cool-season grasses, such as Bentgrasses and Ryegrass, though Bluegrass/Wintergrass (Poa annua) and low-mown Kikuyu are also vulnerable.
The disease thrives in cool, humid weather with prolonged leaf wetness, which frequently occurs in the autumn and winter months, or during heavy, stagnant spring mists.
Symptoms show as small, water-soaked spots, 1 to 5cm, that turn yellow-brown or reddish-brown. In humid conditions, you may see a white or pinkish fluffy fungal growth along the edges. In severe cases, South African golf courses and turf professionals use specialized fungicides to control and prevent outbreaks.
Grain & Stored Product Protection
Research shows that treating stored grains with low concentrations (1.5%) of lavender essential oil before storage significantly reduces fungal infections like Fusarium solani and also repels Grain Beetles.
Fusarium solani is widely present in South Africa and is ubiquitous in agricultural soils and plant debris. The pathogen has a broad host range and causes significant crop diseases.
Potatoes: Fusarium solani is a predominant species that causes Root Rot and Dry Rot in potato production regions.
Citrus: It is responsible for causing Root and Crown Rot in South African citrus orchards.
Field Crops: It is frequently isolated from the roots of Sunflower and Maize seedlings, where it can cause poor stand establishment and severe Root Rot.
Sweet Potatoes: While Fusarium oxysporum generally causes surface rot and wilt, Fusarium solani is associated with deeper, more destructive internal root rot in sweet potatoes.
Garden Spray
Combine 10-20 drops of the essential oil with 1 teaspoon of mild liquid soap and 1 Litre of water. Apply as a light mist over plant foliage and also the soil.
In the Home
Lavender Essential Oil is one of the most beloved and versatile oils in aromatherapy. Its fresh, floral aroma with gentle herbaceous undertones and a soft sweet finish, provides the perfect middle note perfume to pair bergamot, cedarwood, clary sage, frankincense, patchouli, and tea tree.
Lavender essential oil has long been used to ease stress, encourage sleep, and soothe the skin. Use it in sleep and relaxation blends, facial oils and mists, after-sun care products, children’s aromatherapy, bath salts, and natural cleaning sprays.
Whether added to a diffuser, skincare blend, or bath soak, Lavender offers gentle, natural support for relaxation, emotional balance, and everyday wellness.
For a fragrant mosquito repellent:
Blend lavender essential oil with other botanicals like Lemon Eucalyptus, Tea Tree, or Lime to diffuse.
Indoor spray
Mix 10 to 15 drops of lavender essential oil with a 1 teaspoon of soft liquid soap to help the oil disperse, and add to about 1 Litre of water in a spray bottle. Spritz around window sills, door frames, baseboards, and cabinets to repel unwanted 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.
