Thyme is the common name for plants in the genus Thymus. Thymes are fragrant, woody, perennial plants and many species are evergreen. Although they look quite unlike their relatives, thymes are members of the mint family, Lamiaceae.

Thymus vulgaris is known as common thyme or garden thyme, and is the primary species of thyme used in cooking. There are an estimated 350 species of thyme, but there has been frequent confusion, because different nurseries or breeders have given the same common names to separate species or cultivars. For example, ‘lemon thyme’ may refer to several species or cultivars of thyme.

Thyme is rich in fragrant oils, which give it its distinct smell and flavor. The primary components of thyme oil are thymol and carvacrol, which can range in concentration from 20-60% of the total oil composition depending on the species and cultivar. Minor components of thyme oil include gamma-terpinene, p-cymene, trans-caryophyllene, borneol, linalool, 1,8-cineole, and alpha-terpinene.

While we mostly appreciate these oils when we’re cooking with thyme, the plants evolved to produce these compounds for a very different purpose. Like many other fragrant, oil-rich plants, thymes use these oils to defend themselves and deter herbivores. By extracting the essential oil of these plants, we can harness the power of these natural compounds. The essential oil of thyme has been widely studied as an insecticide and antimicrobial agent, and is effective against numerous pests and pathogens. The components of thyme oil disrupt the pest’s cell membrane, increasing membrane permeability. This leads to a reduction in protein synthesis and other widespread physiological changes, inhibiting the pest’s normal development. Thyme oil and its components are effective both as contact insecticides and as fumigants.

 At Apical Crop Science, we sell two products based on thyme oil:

Agropest contains two of the most acclaimed pest control oils available anywhere, and at much higher concentrations than other similar products. The thyme oil (13%) in this product is an excellent endocrine disruptor, suffocant and repellent, while the rosemary oil (10%) destroys eggs and insect tracheas and interferes with neurotransmitters. The combination of these two means that it is effective against every stage of an insect’s life.

Agro Thyme Guard is a 100% biodegradable broad spectrum contact and systemic liquid organic bactericide, fungicide, and insecticide for use in all crops. Thyme Guard has a residual effect up 20 days and is phytotoxic at >2% rate. Thyme Guard has proven its high efficacy against diseases like Botrytis, Fusarium, Powdery Mildew, Downy Mildew, Citrus Canker, Citrus Greening, Fire Blight, and many others.

A photo of fresh thyme to be used in cooking. Image from Flickr.

Pest species which can be treated effectively with thyme oil:

• Various fungal and bacterial diseases
• Acanthoscelides obtectus, the bean weevil
• Sitophilus zeamais, the maize weevil
• Sitophilus oryzae, the rice weevil
• Musca domestica, the house fly
• Spodoptera litura, the tobacco cutworm
• Drosophila melanogaster, the common fruit fly
• Culex pipiens, the common house mosquito
• Ostrinia nubilalis, the European corn borer
• Rophalosiphum padi, the bird cherry-oat aphid
• Agriotes obscurus, the dusky wireworm beetle
• Oryzaephilus surinamensis, the sawtoothed grain beetle
• Brassicogethes aeneus, the common pollen beetle
• Anomala orientalis, the oriental beetle
• Popillia japonica, the Japanese beetle
• Rhizotrogus majalis, the European chafer
• Cyclocephala borealis, the Northern masked chafer
• Spodoptera littoralis, the Egyptian cotton leafworm
• Choristoneura rosaceana, the oblique banded leafroller
• Varroa destructor, the Varroa mite
• Tetranychus cinnabarinus, the carmine spider mite
• Various other mites
• Plutella xylostella, the diamondback moth
• Diaphorina citri, the Asian citrus psyllid, and other psyllids
• Trialeurodes vaporariorum, the greenhouse whitefly
• Bemisia tabaci, the silverleaf whitefly
• Rhyzopertha dominica, the lesser grain borer
• Nezara viridula, the Southern green stink bug
• And many others!

Beneficial species which may be affected by thyme oil:

• Orius species, the minute pirate bugs
• Apis mellifera, the Western honeybee/European honeybee

A variegated cultivar of Thymus citriodorus. Image from Wikimedia.