What causes black rot in succulents in winter?

The cause of black rot in succulents in winter is a fungus called “Fusarium oxysporum”, which can both infect plants and survive in the soil, and is capable of infecting many plants. After a succulent is infected with black rot, yellowing first appears on the leaf surface, with grayish-white lesions on the underside and a grayish-white mold layer, which then spreads to the leaf surface, and finally causes the leaves to curl, dry up and even die. It is a common plant disease.

Normally, black rot tends to appear in hot, stuffy and humid environments, but winter temperatures are lower and the environment is also drier, so why does black rot appear? Qinnongwang here explains for everyone the reasons this disease appears in winter:

1. Watering method

Some friends water their succulents in winter by pouring water straight down from directly above the succulent without a care, so water collects in the leaf center, and coupled with frequent watering, when the weather turns just right with sunshine, the water temperature in the spots where water has collected rises higher and higher, creating a hot, stuffy and humid environment in which black rot is extremely likely to occur, and which also attracts pest infestations;

2. Overwatering

In winter succulents are almost always in a state of halted growth, and in winter they are all placed indoors, where ventilation in winter is very poor. If at this time you still water according to your usual watering amount, the succulent cannot absorb the water, the environment is not ventilated, and over a long period this easily causes black rot to occur.

If black rot has already appeared, then the only option is to cut away all the black rotten parts, then apply fungicide to the cut surfaces, and after some time observe again. If the black rot continues, then you can only steel yourself and throw it away.

So how can black rot be prevented in winter? In fact, winter is indeed not a period of high incidence of black rot. As long as care is proper, black rot can still be avoided. In winter you only need to give the succulent a little water, and pour it directly onto the soil; never pour it from directly above the succulent, and try to keep water from coming into contact with the succulent at all. If you have watered too much, find a well-ventilated place and leave it there for a while; short-term water accumulation or overly moist soil can still be tolerated by succulents.

The above is Qinnongwang's introduction to black rot in succulents in winter. Note that this “Fusarium oxysporum” can survive in the soil, so if a succulent dies after being infected with this disease, the soil it was planted in must be disposed of, and the flower pot must also be disinfected, to prevent the fungus in the soil from infecting other plants.