Fat plants

Cereus - state of health

Question: Cereus - state of health

Hi, my cereus has developed a sort of light brown collar at the base. For the rest it looks healthy. What is it about? It is a specimen that I have now for about fifteen years, another little more than a meter.
Thanks so much,

Answer: Cereus - state of health

Dear Antonio,
it often happens that some diseases make the skin of cacti brown, usually it is bacteria, which penetrate the pulp through the holes left by some insects, such as cochineals, or manifestations of fungal diseases, which develop both starting from the 'external, both starting from the roots, going up again towards the stem passing through the internal part of the plant. This type of parasites, however, does not present the brown spots as the only and only manifestation, but it is also associated with a precarious state of health, with plants that appear soggy, or with rotting parts. In addition to this, the typical diseases of succulent plants, characterized by brown spots on the epidermis, usually have an uneasy appearance: the spots are rounded, in various positions, some are close to the coletto, others higher. Dark stains can also give rise to previous damage to the cuticle that covers the stem of the succulent plants, such as hail damage. Clearly, even in this case, it should be damage diffused in more parts of the stem, and placed above all at the apex. In your case, your plant appears healthy and vital, with the apex developing over the years, and some dark and brown spots towards the base; I think it could simply be the normal lignification, which adult succulent plants face: the oldest part of the plant loses its characteristics, and a lignified fabric takes the place of the green and spongy one, which is able to absorb water , usually present in these plants. If your plant does not show any other kind of discomfort, and you have been treating it for more than fifteen years, I believe that this is nothing to worry about, but only about the normal physiological development of a succulent plant. Keep your plant in the sun, with good lighting, and water it only when necessary; now that your wax is "old" you can also avoid periodic repottings; from March to September it mixes the water used with a specific fertilizer for succulent plants, poor in nitrogen and rich in potassium, every 20-25 days.