From the wormwood plant, it is possible to obtain an effective natural insecticide. This plant, also known as Greater Wormwood (scientific name Artemisia Absinthium), has excellent medicinal properties that, if properly extracted, can help us in the biological defense of our vegetable garden.
Its most famous use is undoubtedly in the preparation of the liqueur absinthe. In 19th and 20th century France, it was widely used among the “accursed poets” for its hallucinogenic effects, due to certain substances contained in its essential oil. However, this aromatic herb has been known and used since ancient times, especially for its antiseptic and vermifuge properties. It can also be utilized in agriculture, thanks to the preparation of a natural wormwood macerate.
Let’s learn more about the wormwood plant and its properties, starting with its botanical identification.
The Wormwood Plant (Artemisia Absinthium)
Wormwood is a perennial herbaceous plant belonging to the large family of Asteraceae or Compositae.
According to scholars, the Artemisia genus includes about 400 species, distributed worldwide, especially in temperate areas of the northern hemisphere. In our country, there are over 30 species present in the wild. We will focus our attention on the most well-known and widespread one.
The wormwood plant is found in the wild up to 1000 meters above sea level, in uncultivated and arid fields, sunny slopes, road edges, rocky and stony places.
It is a chamephytic shrub, meaning that it has woody basal parts, giving it a shrubby appearance. It is also deciduous, meaning that in autumn, the herbaceous parts dry up and fall off, leaving only the woody parts alive. The vegetative growth resumes at the beginning of spring.
Roots and Stem
The plant’s roots are secondary and originate from a branched rhizome. The stems, both sterile and flowering, also originate from this rhizome.
The stems are erect, ranging from 40 to 90 cm in height, semi-woody at the base, and branching in the upper part. They have a gray-green color and are covered with a silvery-white down.
Leaves and Inflorescence
The leaves of the wormwood plant are pubescent, light green on the upper side (tending to white due to a slight fuzz), and white on the lower side. They have oval-shaped contours with a progressively narrowing petiole as it goes upwards. Their main characteristics are their intense aroma and extremely bitter taste.
The inflorescence of the Artemisia Absinthium plant is a terminal panicle. It consists of small flower heads, with a pendulous posture and golden color. The flowering usually occurs in the months of August and September. Care should be taken during harvesting in this period, as the pollen is highly allergenic.
As mentioned, the wormwood plant has long been considered medicinal, with numerous properties. What is used are the leaves and flowering tops, which contain an essential oil composed of the monoterpene thujone, which we have already encountered in our discussion of sage. The essential oil also contains sesquiterpene lactones.
Other contents of the wormwood plant include bitter principles, flavonoids, tannins, silica, polyacetylenes, antibiotics, inulin, and hydroxycoumarins.
There are also two bitter principles of glucosidic nature: absinthin and anabsinthin.
Furthermore, the wormwood plant contains artemisinin, a very potent active ingredient found in another widely used herb in herbal medicine: Artemisia annua.
All these substances give wormwood various medicinal properties, such as: vermifuge action, favoring the elimination of intestinal parasites; cholagogue action, improving bile secretion; febrifuge properties, helping to reduce body temperature in case of fever.
It must be noted, however, that this plant has some toxicity, so it should be known and handled with care. For this reason, we discourage the preparation of homemade infusions for internal use or lotions for external use. Instead, ready-made essential oil with controlled amounts of active principles can be easily found online.
The plant is also still the subject of study in the medical field today.
Wormwood Macerate as an Insecticide
What interests us in this discussion is the use of wormwood macerate as a natural insecticide. Recently, it has been proven that the sesquiterpene lactones contained in the plant have a strong insecticidal and repellent action.
This macerate is effective in keeping away ants, snails, mites, aphids, and cabbage worms.
It can, therefore, be used on plants along with other natural macerates that we have learned about in our investigations. These include the infusion and macerate of garlic, nettle macerate, decoction and macerate of horsetail, fern macerate, and macerate of tomato leaves and females.
Preparation of Wormwood Macerate
Both fresh and dried wormwood plants can be used for the preparation of the macerate.
The dosage involves using 300 g of fresh plant or 50 g of dried plant in 10 liters of preferably rainwater.
A hard plastic container should be used for the maceration, which should last about 6 days.
The macerate produces a whitish foam that covers the surface, so it should be stirred once a day to promote oxygenation.
The container should be kept open and in a sunny position to enhance the plant’s decomposition.
When the mixture stops foaming (as mentioned, it takes about 6 days), our macerate is ready and can be filtered with a jute sack.
Once ready, it can be diluted with water in a ratio of 1 to 2, i.e., one liter of macerate in 2 liters of water.
How to Use It
This solution can be sprayed directly on the plants, preferably in the evening, using a backpack sprayer (if you don’t have one, you can find it here).
For Severe Infestations
If the infestation is severe, it is advisable to repeat the treatment every 2-3 days. To preserve the macerate, we suggest using dark-colored glass bottles, to be kept in a cool and shaded place.
The macerate can be kept, without losing its effectiveness, for a couple of months.
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