Essential oils are becoming more popular than ever for agriculture. This is thanks primarily to being natural substances that are less harmful for the environment compared to synthetic chemicals that may leave lasting damage on people and the planet. Synthetic herbicides and pesticides have a long history of negative effects, whereas essential oils may be a healthier and equally effective alternative in many cases.
What Are Essential Oils and How Do They Work?
Essential oils are naturally-occurring chemical compounds that are derived from plants. Almost every plant contains essential oils, including a number of fruits, vegetables, and even some seeds. These essential oils are extracted from plants using safe and environmentally-responsible steam-distillation, and are then bottled without further processing or adulteration.
Steam distillation is a process in which water is boiled and steam is sent through the areas of the plant containing terpenes and essential oils, such as the leaves, bark, and sometimes flowers. The steam releases the molecules in the plant that are aromatic, and the vapor goes through a condenser which strips away the water, leaving pure essential oil.
While essential oils are all-natural, they are also known for their potency. Many of them have strong aromatic and therapeutic qualities (thus their popularity for aromatherapeutic purposes), yet they’re still far safer than synthetic chemicals when used properly.
Though it’s often recommended to only buy the most expensive, highest-grade essential oils possible when using them therapeutically, topically, or internally, essential oils for agriculture can be sourced much more affordably. Commercial-grade oils, which are still 100% safe and natural distillations of plant material that have been blended from various distillation batches to achieve standardized aromas and effects, are perfectly acceptable and often preferred due to their price-to-performance ratio.
Many essential oils are known for having antimicrobial, antibacterial, and other pest-removing or repelling properties, which is the main reason why they’re efficient at pesticide and disease control on crops.
Peppermint, eucalyptus, and wintergreen have been proven scientifically to kill many insects. While they don’t kill bugs on contact, the bugs do perish eventually if they’re exposed to lots of the oil at once, and the presence of the oil will prevent them from entering an area in the first place.
Cedarwood oil has been found to repel the larvae of moths because of its strong, woodsy aroma, just like cedar trees themselves. Cedarwood effectively protects against many kinds of insects, making it another great all-purpose pesticide essential oil.
Lavender oil is highly effective in deterring fleas, beetles and flies with a calming floral aroma. This essential oil can also be applied topically when mixed with a carrier oil to soothe insect bites, prevent inflammation and control the spread of infection in that area.
While jojoba oil is a carrier oil and not technically an essential oil, it still has natural protecting abilities. Jojoba oil both kills and repels whiteflies on all kinds of crops, and can also kill powdery mildew on grapes and ornamentals on contact. Because jojoba oil is a carrier oil, it may be a better fit for crops with a more delicate aroma, as there won’t be as much of an aromatic element. The pesticide powers of jojoba can be combined with any of the above pesticidal essential oils to amplify the effects of both.
Research is being done on essential oils for use on crops to prevent disease. The main essential oils thought to prevent disease on crops are those that have antibacterial as well as antimicrobial properties, such as mint and eucalyptus.
Which Essential Oils make the Best Herbicides?
When it comes to herbicides, cinnamon oil and clove oil are great choices, though peppermint, tea tree, and more are often used. In scientific studies, cinnamon and clove oils were effective when applied to ragweed and johnsongrass, which are two popular pest plants, and many people use these and other oils to eliminate unwanted plants of all kinds.
The reason why cinnamon and clove oil work so efficiently against these weeds is due to their naturally-occurring eugenol content. This component paired with the molecules that give cinnamon and clove their smoky but almost sweet fragrances gives the oils a boost when it comes to herbicidal properties on many plants, though their efficacy hasn’t been formally tested beyond ragweed and johnsongrass.
Benefits of Essential Oils vs Conventional Pesticide & Herbicide Methods
Conventional pesticides and herbicides do have a high rate of efficacy when it comes to the prevention of pests and unwanted plants. However, these solutions are often filled with toxic, harmful chemicals that have been proven to cause environmental damage as well as the potential to harm those who handle, work, and live near the chemicals.
Since essential oils are naturally occurring plant materials, there is less of a chance of soil damage and other environmental impacts compared to many synthetic substances. While essential oils aren’t supposed to be ingested or applied to bare skin, their vapors also tend to be safer than artificial pesticide and herbicide solutions, which makes essential oils safer for people and the planet.
There are some drawbacks to essential oil pesticide and herbicide methods. For instance, essential oils may not be quite as effective as artificial chemicals. However, those same chemicals may be doing damage to organic life that isn’t intended to be in the path, and in many cases the excessive potency of artificial products is more than is needed.
Essential oils may also be a bit more expensive than conventional herbicides and pesticides when widely applied. If you’re thinking about trying essential oils in your agriculture, it may be worth it to start small to get a feel for the difference before diving in.
It may be tempting to just buy a gallon or two of your choice of essential oils and pour them on crops, but the herbicidal and pesticidal nature of essential oils is reduced unless the essential oil is used in a mixture.
For herbicidal uses, it’s best to mix the cinnamon, clove, or other oil with a surfactant and water. You can mix your own with 9 parts water, 1 part oil, and a splash of surfactant like household dish detergent.
For pesticidal uses, mix 15 drops of essential oil with every 4 ounces of water. You may also want to add an emulsifier, such as witch hazel, castile soap, or polysorbate 20, but you can also just shake the mixture vigorously before. This can get tedious if you’re working with large quantities, so we recommend purchasing a large 5-pound container of your chosen essential oil and premixing your solution.
Safe and Effective Pest Control with Essential Oils
Essential oils are a great way to keep pests and unwanted herbs away, and may be able to help with diseases that affect crops. If you’re thinking about implementing an essential oil herbicide or pesticide plan and still have questions, please reach out to our customer support team at support@wholesalebotanics.com: we’d be happy to help!
SOURCES
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909281/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143296/
https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_G-114_01-Jul-01.pdf
https://www.hawaii.edu/news/2020/09/22/essential-oils-and-organic-crops/
https://www.sciencedirect.com/science/article/abs/pii/S0278691507004541
https://apsjournals.apsnet.org/doi/full/10.1094/PDIS-05-15-0574-FE