Spots on succulent plant

Spots on succulent plant

Question: spots on a fat plant


my catcus, now twenty years old, give me beautiful flowers of a soft pink color and intense aroma all summer long. Unfortunately, on the outside they are covered with brown spots that over time have dried up ruining the plants from an aesthetic point of view. How can I remedy or stop the disease? Thank you so much

Answer: spots on a fat plant


Dear Stefania,
brown spots on your plants can result from various external agents, such as fungal diseases, excessive sunstroke, red spider mites, normal plant development, depending on where the spots are and their appearance. Your cacti, very adaptable to various cultivation conditions, which produce beautiful pink flowers in summer, are most likely echinopsis, very widespread plants thanks to their splendid and showy flowering, commonly known as honeymoon (a name that ironizes that the flowers open for only one day, and close again in the evening). If the plant has brown spots, which tend to become soft and dark, then it has been attacked by a fungal disease, which will be eradicated using a fungicide, to be sprayed onto the epidermis of the cactus, or even added to the water of the watering, or otherwise from the outside the fungus will penetrate inside, killing the plant. If the spots are rust colored, and are roundish and plastic in appearance, which seem to float on the skin of the cactus, without affecting the pulp towards the inside, these could be problems related to the bites of small insects, such as scale insects, which have then heal, leaving however a clear sign of their presence and maybe some fabric ruined by any bacteria present on the insect; if the stains are dry and stiff, you don't have to worry: they are unfortunately indelible, but they are not causing problems to your plant. Brown, wood-colored, slightly depressed spots, starting from the base of the stem, and which simply look like dried skin, as if dehydrated, can simply be a manifestation of the normal evolution of your plants, which you claim to have for many years: even cacti, after many years, they lignify in the lower part, just like non-succulent shrubs do. This type of problem is simply linked to the growth of plants, which tend to form a more rigid and robust base; if you search the internet for photographs of lignified cacti you can compare the spots with those of your plants. Another cause of dark spots are the mites, also called red spiders; around the spots you should also see thin webs, but you may not see the mites, which are tiny; these arachnids feed on the sap contained in the plant, and they sting it to extract it, since the colonies are very large, they tend to produce enormous speckles, often located in the youngest part of the plant (but it is not said). Against these mites it is necessary to intervene using appropriate acaricides, because they are often immune to the action of insecticides. Other spots may be due to external reasons such as: hail from last year, a fungicide or an insecticide supplied in summer with the plant exposed in full sun, bumps, a cat with its nails engraving the stem of the cactus. In any case, if they are not followed by soft and yielding areas, these are not serious problems.