Dear Luciana,

azaleas are among the most used plants in Japan to form bonsai; the fact that these plants produce small leaves, and even small flowers, with wrinkled and twisted stems, makes them perfect bonsai, with great satisfaction for growers. Unfortunately they are not very easy to grow plants, and in my opinion they are not a good bonsai to start from, especially if you live in Reggio Calabria. Azaleas belong to the rhododendron genus, and are native to most of the globe, even in Italy there are some endemic species; the Italian species are widespread in the Alps and the Apennines, while the areas of Asian origin are Tibet, and the highlands near the Himalayan mountain range; they are therefore plants used to living in a cool and humid climate, very different from that present in your city. If you read any azalea bonsai cultivation manual it will advise you to place your pot in a place where it enjoys a few hours of direct sunlight, well exposed to air and light, with good humidity. Honestly, a combination of this type, in Reggio Calabria, I think it is difficult to obtain, because the sun is scorching, from May to September, and the air is brackish, given the proximity of the sea. The result is a dehydrated plant; if to compensate for the lack of humidity, you go to water it very often, the soaked soil will favor the growth of fungi in the growing substrate, with great ease. Azaleas are acidophilic plants, and as such they do not like water rich in limestone, and need a suitable soil; in the case of bonsai azaleas, a specific soil for acidophilic plants is used, called Kanuma, which is not easy to find anywhere in Italy. Therefore, the problems that make the leaves yellow can be many: too dry air, excess of direct sunlight, brackish air, calcareous water. The water problem is solved quite easily, in addition to providing the correct soil, it is good to prepare a watering can full of water, even from the tap, and let it rest for at least a couple of days, before using it for watering, so that the limescale settles; being a single bonsai, a full watering can is enough for days. As for the heat and the sun, keep your plant in a semi-shaded area from May to September, away from direct but well-lit sun. Avoid exposing it to strong winds, if it comes from the sea; and frequently vaporize the leaves, with the water from the irrigations, to improve the ambient humidity, but do it in the early hours of the morning, not in the hot hours of the day, and not in the evening.