The natural defense of the garden can be made use of many means for rid the cultivated plants of harmful parasites, the use of natural decoctions and macerates is particularly interesting because in addition to having no consequences on the environment, it is a no cost. So let's find out below the properties and preparation of the tansy infusion, a self-production that can be really useful in the vegetable garden. Other useful recipes can be found on the page dedicated to natural preparations.
The tansy (tanacetum vulgare) is a spontaneous plant of the composite family, typical of country meadows, easily recognizable at the time of flowering due to its yellow ball flowers very characteristic. We can find it more or less throughout the Italian territory, but if we do not have where to collect it spontaneously it is easily cultivable.
In tansy there is an oil called thujone which makes the plant toxic and has an antiparasitic effect, for this reason a decoction can be obtained which is useful for the defense of the vegetable garden. The use of tansy against parasites is particularly useful to repel insects of the genus of lepidoptera, such as noctuids, agrotids, moths and borers.
How to prepare the decoction of tansy
There preparation of the decoction or infusion of tansy is very simple: first you need to get the plant, in the preparation we can use all the aerial part (therefore flowers, leaves, stem), avoiding only the thicker stems. We can use both fresh and dried plant.
To prepare the infusion, the water must be boiled, once it has boiled, the fire is turned off and tansy is added, leaving to infuse for half an hour. The procedure is the same as we use to prepare a tea or herbal tea, extending the infusion time to extract the useful substances at their best.
Later we will go to filter the liquid, throwing away the plant residues so that you can spray the decoction with a nebulizer. Before using our natural pesticide we will go to dilute it with more water.
The ideal is to always use rainwater, free of disinfectants such as chlorine and not excessively calcareous.
Dosage of the infusion
To make the decoction, approx 50 grams of fresh tansy per 100 ml of water. If you use dry tansy instead, 5 grams of plant will suffice. The infusion obtained in this way will go then diluted in water, in the proportions of 1 to 10. Then, once diluted, we will have a liter of infusion for every 50 grams of fresh tansy (or every 5 grams of dried plant).
In all these herbal preparations the dose is not binding: the more tansy we use, the more concentrated the result will be. A stronger decoction can be diluted more or less can be used in the treatment phase.
How tansy is used in the garden
Once the tansy infusion has been prepared, we can use it in the garden. L'repellent action of the preparation has a wide spectrum, but the insects against which to use it with the best results are the moths, among which we remember the noctuas, the cabbage, the borers and the moths. The decoction also repels the altica and aphids.
The repellent effect on anchovies and lepidoptera makes this preparation a particularly treatment useful for growing cabbage and in general of all cruciferous plants, which are among the most oppressed by these insects.
For do treatments of tansy the diluted substance is sprayed directly on the plants, it is advisable to avoid doing it in too sunny hours and instead favor the evening. Use can be preventive, by spraying once every 10 days for the entire duration of cultivation, there are no contraindications linked to phytotoxicity. The decoction can also be used when the insect is already present, taking into account that it is a mild remedy and that in that case perhaps it is appropriate to use more drastic methods, such as an organic insecticide (for example neem oil).
For safety it is advisable not to treat with tansy decoction at least one week before harvest, in order to prevent toxins from going on the vegetables that will then be eaten.
The properties of tansy
Over the years, the tansy plant has had a medicinal use, it was included among medicinal plants and was used in particular against intestinal worms or in the case of aerophagia. They also made compresses based on tansy to be used to soothe toothaches.
The toxins contained in this plant, however, make it inadvisable to use it for food, much better to use tansy against insects in the garden and orchard, exploiting the toxicity for a just cause.