Essential oils are usually used for home fragrance and relaxation. However, they have been used as insecticides for many years.
Some of the essential oils have been confirmed to be effective natural repellents to work against cockroaches.
In this review I have provided a list of most popular and effective essential oils for roaches.
Oregano oil is considered one of the most effective from essential oils to repel cockroaches. It also has demonstrated the most toxicity against roaches in the study.
According to the research, it stays effective for up to a week after application. In some cases, it was still working for 10 days or more after treatment.
You need to mix several drops of essential oil with water and apply it to areas which you would like cockroaches to avoid. This should keep cockroaches away for a few days.
Rosemary oil was found to be most effective for treating cockroaches in this scientific study. It caused a 100% mortality rate against roaches at low concentration starting with only 2.5%.
Cockroaches need to come in contact with rosemary oil to be killed. You can build a homemade trap for cockroaches and add rosemary oil or use it in the fumigation process.
Eucalyptus has quite a strong smell which you most likely are familiar with. It is also confirmed to repel cockroaches effectively. Eucalyptus oil comes next after rosemary oil and oregano oil as it demonstrated a 100% mortality rate at a 5-30% concentration level.
Mix 10 drops of eucalyptus oil with 3 oz of water. Spray this mixture around the areas where you think cockroaches might be hiding.
Eucalyptus oil is a good all-round natural treatment for roaches and can be used at home where you have pets.
Yarrow also known as Achillea is an erect perennial herbaceous plant that grows up to 3 feet in height native to warm regions of Asia, Europe, and North America. For outdoorsy people, it is known to be useful for stopping bleeding effectively.
Yarrow oil for roaches is not as toxic as the ones mentioned above. It has demonstrated 100% mortality rates for cockroaches at the higher concentrations of 45% to 100%. While it is effective, it does not last long.
Peppermint oil or mint oil is a potent liquid and does have quite a strong scent. Many homeowners claim that it is good natural repellent for pests. Mint oil contains high concentrations of natural pesticides which repel some insects.
In the research the lowest mortality rate of 97.2% was registered from mint oil after 24 hours when other oils demonstrated 100% mortality rate. However, speaking in scientific terms it was not significantly different from other oils.
According to the studies mint oil was found not only to repel pests, but also demonstrated to be toxic to american and german type of cockroaches.
Add a few drops of mint oil to water and spray on walls around your house to repel roaches. You can also soak cotton balls into the mixture and place where cockroaches may appear. For a stronger solution add 1 part of vinegar to 2 parts of water.
Please note that undiluted peppermint essential oil may result in skin irritation, rashes or allergic reactions if applied directly on skin.
Lavender oil has a really nice smell and can be used as fragrance at home. While lavender oil is considered to repel insects such as flies and fleas, its effectiveness to repel or kill roaches has yet to be confirmed.
According to a study you can combine lavender oil with other essential oils such as citronella, lemon, rose and basil oil. Add water to the mixture to produce insect repellent which can repel flies, gnats or fleas.
Citronella oil is used in many insect repellent products. Citronella essential oil has shown insects repellent properties on mosquitoes, flies, gnats or other bugs.
Citronella essential oil effectiveness as repellent against cockroaches has been proved in the scientific study. Unfortunately the effect on cockroaches lasts only for an hour or two.
Tea tree oil
Tea tree essential oil is usually used as an antiseptic. Some of the sources claim that tea tree oil does not repel insects and especially cockroaches.
In case you would like to go ahead with treating cockroaches with tea tree oil it is recommended to mix with other essential oils. Mix several essential oils as it may be more effective in combination with other natural repellants.
Catnip has been used in traditional medicine for ages as sleep aid and help from stomach upsets. Cockroaches hate catnip oil smell and it is considered to be quite decent cockroach repellent.
Catnip plant essential oils contain nepetalactone that repel insects. Research study has indicated positive effects of catnip extracts and essential oils as a repellent for cockroaches (especially german cockroaches).
Mix a few drops of catnip essential oil with 1 part water and 1 part rubbing alcohol. Spray where you think cockroaches might hang-out. You need to re-apply the solution quite often as the effect lasts only up to an hour or two.
Cedar tree is widely used in closets and storage areas because it smells good and keeps your clothes fresh.
Cedar oil not only smells good but it is also a natural insecticide. Main component in cedarwood oil is cedrol and cedrene. Both those materials combine cedar camphor.
This chemical compound is effective in fighting bugs including cockroaches. Insects are not comfortable in breathing the oxygen produced by cedar trees, which have the same properties as contained by cedar essential oils.
Mix cedar essential oil with rubbing alcohol and spray the solution around your house.
Cypress oil is made from the stems, twigs and leaves of cypress trees. Cypress is natural insect repellent. Sometimes it is even recommended to use cypress mulch in the landscaping to repel insects.
Mix cypress essential oil with peppermint oil to produce a natural cockroach repellent at home. Add 8 drops of cypress oil into the 1/2 cup of water and a 10 drops of peppermint essential for stronger effect.
Pour the mixture into a spray bottle and spritz corners and hiding spots for cockroaches in your home.