It can be found on almost all plants, particularly targeting tender greens. In specialty stores, you can purchase anabasine or nicotine sulfate. Use this solution (instructions for dilution are provided on the package) to spray the flower on your balcony, and keep it outside for 3 to 4 days before bringing it indoors. Afterward, the plant should be thoroughly washed. The best remedy is a tincture made from tobacco, onion skins, or garlic (using 10 grams per liter of water). Boil it in the evening and let it steep overnight. In the morning, spray the mixture on the plants.
The true scale insect thrives on houseplants with lush foliage, such as palms, laurels, cacti, citrus trees, oleanders, and ficuses. It can only be eliminated manually, as this pest attaches itself to the greenery. Soak a cloth in a tobacco solution, add a bit of soap (for viscosity), and carefully wipe each leaf.
Powdery mildew (a type of disease) most commonly appears on roses. Therefore, it’s advisable to spray the bush with a three percent solution of iron vitriol (30 grams per liter of water) before the buds open. If a white coating appears on the leaves, it should be rinsed weekly with a 0.5 percent solution of copper vitriol (5 grams per liter of water).
For amateur gardeners, I recommend washing the stems and leaves with water mixed with laundry detergent (one tablespoon per liter of water).