Commercial garden pesticides often contain lethal and toxic chemicals that impose many health risks; why not use some of the many different aromatic plants available as natural insect and pest repellents instead?

The Lamiaceae plant family probably contains the highest number of plants that are widely available for many gardens. Just as some essential oils are used as natural insect repellents for yourself at this time of year, plants such as lavender, thyme, rosemary, sage and mint naturally repel some of your unwanted guests in the garden – for both you and the plants! Here’s a quick look at three of those Lamiaceae plant species mentioned.

Why do Some Aromatic Plants Repel Insects and Garden Pests?

Plants are made up of complex chemical components such as alkaloids, terpenes, phenols and aldehydes; essential oils are extracted from plants and used for different therapeutic purposes arising from the chemical combination of these components, including those used as an insect and pest repellent. Therefore, it is only logical that the source of essential oils, the plant, might contain similar properties (depending upon the plant).

Scientists and botanists are still not certain exactly how the complex make-up of plants works in repelling insects and other critters. Research studies are continually carried out. According to Valerie Worwood in The Complete Book of Essential Oils and Aromatherapy, it is believed that the aroma of plants are the key to controlling unwanted insects, pests and critters in the garden. Whatever the scientific reason is behind plants and natural pest control, many gardeners believe in the concept and have success in controlling pests naturally.

Mints for Pest Control

There are various types of mint to choose from for the garden but the two most useful species of mint for pest control in the garden are peppermint (Mentha piperita) and spearmint (Mentha spicata); uses include:

• ants (spearmint and peppermint)

• aphids (spearmint)

• cabbage white butterfly (peppermint)

• fleas (peppermint)

• lice (spearmint and peppermint).

Lavender for Insect Control

There are also many varieties of lavender to choose from for the garden including true lavender (Lavandula angustifolia), lavandin (Lavandula x intermedia), spike lavender (Lavandula latifolia) and many lavender hybrids. Lavender is covered in more detail in the Sedona Aromatherapie short course on lavender. Lavender is recommended for the control of:

• fleas

• mosquitoes

• moths.

Thyme for Controlling Pests in the Garden

Common thyme (Thymus vulgaris) is a flowering, medicinal herb. One of the major components of thyme – thymol – is used to control the Varroa mite, a parasitic species to bees; the use of thymol in this way helps to maintain the bee species, important pollinators of various plants, including the sunflower and the herb fennel. Thyme also has the following uses for the control of garden pests such as:

• bean beetle

• cabbage root fly

• cabbage white butterfly

• carrot fly.

The Lamiaceae Plant Species for Garden Pest Control

The Lamiaceae plant family may contain the greatest number of natural pest repellents but there are also many other plants from other plant families that you can also use to control garden pests; the one thing that these plants have in common is the fact that they are fragrant. They also make an attractive addition to any garden!

References:

• Report: Green Chemistry and Sustainable Agriculture: The Role of Biopesticides, Karen Peabody O’Brien, Shari Franjevic, Julie Jones (September, 2009), accessed July 1, 2013

• Worwood, Valerie Ann, 1991, The Complete Book of Essential Oils and Aromatherapy USA: New World Library

• Lawless, Julia, 1995, The Illustrated Encyclopedia of Essential Oils UK; Thorsons