Question: Sick Camelia
The leaves of my camellia have small brown spots that enlarge in the lower part. Is it a disease or are they insects? How should I treat it?
Answer: Sick Camelia
It is difficult to diagnose a plant problem without seeing at least one photo; as for the camellia, it often happens that these plants are hit by fungal parasites, especially if the watering is excessive, and the soil in which they are grown has problems related to drainage. At the time of planting, whether you want to cultivate it in pots, or whether you are planting it in the ground, you need to pay close attention to the drainage of the soil in which a camellia is placed; these plants very much fear water stagnation, and being also shrubs which are usually given regular watering, it is clear that the risk that the roots see problems linked to rot (due to excessive humidity) is decidedly high. In general, mixing sand or pumice stone in the camellia soil helps a lot, because in this way a decidedly more porous substrate is prepared, which allows the water to flow quickly. In addition to this, although it is important to water the camellias regularly, it is also advisable to water them only when the soil tends to dry, leaving them completely soaked in water. Once a camellia shows significant signs of fungal diseases, due to excess watering and permanence in always wet soil, it is good to let the soil dry, thin out the watering, and provide the plant with a systemic fungicide.
The dark spots on the foliage may also be due to scab; in this case it is good to remove the leaves affected by the fungus, and destroy them (even the fallen ones), because the spores survive, and give rise to new fungi; afterwards it is good to vaporize the plant with a copper-based fungicide.