Plant protection. You can protect plants from fungal infections or insect damage using herbal preparations. They can be be used preventively, or at the first sign of problems. As they are not chemical poisons, it is perfectly safe to eat the fruits or vegetables after treatment.
Field horsetail (equisetum arvense) concoction. This is a very powerful antidote to fungal diseases. The horsetail should be picked towards the end of the summer, at the end of August, when it contains its highest amount of silica, and dried in a shaded environment. The dried horsetail can be used as a fungicide throughout the year.
The concoction is prepared by heating 300 grams of dried horsetail in 5 litres of water for an hour over a low heat. Then you strain it to remove the solids, and dilute the liquid with a further 25 litres of water, stirring the mixture constantly for 10 minutes. The liquid must be allowed to stand for 10 hours before use.
Fruit trees should be sprayed on a sunny day after rainfall, either preventively, or at the first sign of fungal disease. When used preventively, one can follow the instructions in a monthly crop calendar.
You can also use the horsetail concoction from a watering can, or create a horsetail 'bath' to soak the roots before planting fruit trees. As a spray, the horsetail concoction can be used on any part of the trees, including the crown, trunk and fruits. It provides exceptionally effective resistance, as well as cure, for fungal diseases such as powdery mildew, downy mildew, and rust fungus. Experienced farmers say they cannot have too much horsetail! I spray my vines and vegetables with it. The mixture of 30 litres, as described above, is enough for 400 vines and the vegetable garden covering an area of 400 m2.
Yarrow (Achillea millefolium) concoction. Yarrow is one of the medicinal herbs used in folk medicine, as it contains bitter-sweet etheic oil and many minerals. It also has disinfectant properties. It enhances the action of other mixtures, therefore it can be mixed with them for greater efficacity, especially with mint and camomile. In organic agriculture it is used against powdery mildew, fruit rot and other fungal diseases.
The yarrow concoction is prepared from 1 kg of leaves and stalks (15cm long), or 200 g of dried yarrow cooked in 10 litres of water. This is then strained to remove the solids, and the liquid is diluted in a ratio of 5:1. It is good as a preventive spray, or at the first signs of illness. For the best effectiveness, make a mint or camomile concoction and mix it with the yarrow in the same dilution of 5:1.
I use this concoction on my vines and fruit trees.
Caution: some fruit trees may show allergy to yarrow in the form of a 'rash', so try out the concoction first on one part of each tree, and avoid using it if there is a reaction.
Nettle (urtica dioica) spray. This is used as an insecticide to eliminate aphids. At the same time, the nettle spray strengthens the plants, fertilizes them and increases their resistance against damage.
To prepare the spray, soak 1 kg of finely chopped nettles in 10 litres of water for 24 hours - no longer than that, or the preparation will lose its strength. If you do not have fresh nettles, you need 100 to 300g of dried nettles. Strain the mixture and use the liquid to spray the plants from all sides. The nettle residue can be composted. (The quantity of the spray and its dilution ratio can be altered to suit individual needs.)
Important: the nettle spray must be used immediately, never more than 2 to 3 days after it has been made, otherwise it can cause severe burn damage to your plants.
The nettle spraying can be repeated after a few days, using a fresh preparation.
I use this concoction most often on my vegetables, more rarely on the vines.
Wormwood (artemisia absinthium) concoction. This is very bitter, so insects avoid it, which makes it a very effective insecticide. To prepare the concoction, put 300g of dried chopped wormwood twigs (which can include leaves and even flowers) into 1 litre of boiling water and leave immersed for half and hour. Strain the liquid to remove the solids, add 9 litres of water and the spray is ready for use. The wormwood concoction is used to protect strawberries and blackberries from mites. It protects all fruit trees from aphids, caterpillars, ants and other harmful insects.
Caution: the wormwood residue must not be composted.
NOTE In Split, the dried plants used for these preparations can be obtained from kiosks in the market behind the old Hajduk football ground.
The approximate price for each of these organic materials is 75 kunas per kilogram.
© Mihovil Stipišić 2017. (translated by Vivian Grisogono)