Causes and Solutions for the Problem of Hydration and Black Rot in Succulent Plants
You may not be familiar with the related content of succulent plants, the causes and solutions for the hydration and black rot problems in succulent plants. Let's get to know together.
Summer talk about black rot, but summer is high temperature and humidity, and mold is everywhere. Many things in the house are prone to mildew, such as food, clothing, and damp walls, etc. There are so many types of plants, why do they especially like succulent plants? Especially why do succulent plants easily become hydrated and rot in summer? At the same time, what are the differences and connections between hydration and black rot? To understand and solve these problems, we must first talk about the characteristics of succulent plants themselves.
Only by understanding the succulent plants themselves can we understand the causes of black rot, and then minimize the probability of black rot occurring. After all, we don't want black rot to happen, prevention is better than cure!
First of all, what are succulent plants?
Succulent plants refer to a type of plant with thick and juicy appearance, where a part of the plant's nutrient organs, such as stems, leaves, or roots (a few species have both parts), has developed thin-walled tissue for storing water, mainly growing in arid or semi-arid regions for part of the year, where the roots cannot absorb water for a long time each year and rely on the stored water in their bodies to maintain life.
Secondly, let's take a look at the metabolic ways of succulent plants.
The original habitats of most succulent plants grow in arid or semi-arid regions for part of the year, so the metabolic ways of succulent plants differ from those of most plants. Their characteristic is that the stomata close during the day to reduce transpiration (this is very important) and open at night to absorb CO2. This is because the nighttime temperature is lower, so the water lost through the stomata is much less than during the day, which is beneficial for the plant to avoid excessive water loss. This way was first discovered in Crassulaceae plants, hence the name Crassulacean Acid Metabolism (CAM). This metabolic way of succulent plants is one of the reasons for their hydration and black rot!
The high-temperature season in the original habitat coincides with the water-deficient season. To reduce transpiration, succulent plants will close during the day. However, in our home-growing environment, high temperature is combined with high humidity. Compared to the original habitat, the large environment is not short of water, and in some places like Zhejiang, Fujian, Guangdong, and Guangxi, it is humid all year round. Combined with our regular watering, succulent plants in both the large and small environments are in a state of abundant moisture compared to the original habitat.
Succulent plants, which should be in a dormant or semi-dormant state due to drought and high temperature, absorb a lot of water, and because of their metabolic habits, the stomata close during the day to reduce transpiration. These two reasons combined cause the hydration problem in succulent plants. In other words, the succulent plants that have drunk enough water expand and contract with heat in high temperatures, bursting the cell walls. At this point, the leaves of the succulent plants become transparent from bottom to top, which is called hydration. If emergency treatment is not carried out at this time, mold will take advantage of the situation, leading to black rot! In mild cases, only the bottom leaves become transparent and hydrated, while in severe cases, black rot spreads from the rootstock to all the leaves, and at this point, you can only cut the top or completely discard the plant.
Besides, when it comes to black rot, root mealybugs must be mentioned.
Root mealybugs belong to the Homoptera, Mealybug family. The most common species in potted flowers are Hibiscus root mealybugs and cactus root mealybugs, which occur throughout southern China. Root mealybugs have no shell, are milky white in color, and are only 0.9 to 2.2 millimeters in length, elliptical in shape. Due to their small size, they are easily overlooked by people. Root mealybugs live in potting soil all their lives and can have three or more generations a year. In greenhouses, they can occur all year round. Root mealybugs feed on plant juices, but in the original habitats of succulent plants, there don't seem to be many creatures living on the juices of succulent plants. Why do root mealybugs cause black rot so easily?
Root mealybugs cause black rot as a result of the interaction between their breeding habits and the plant characteristics of succulent plants. Summer is the season of root mealybug outbreaks, and most succulent plants are in a dormant or semi-dormant state, with reduced plant resistance. The massive absorption of plant juices by root mealybugs, combined with the reduced resistance of the plant and abundant moisture, leads to a fungal outbreak. It is not uncommon to see a plant fully hydrated one night and completely blackened the next day.
To deal with root mealybugs, the key is to do a good job of prevention in spring and autumn. First is the prevention of soil, which should be disinfected before use, either by sunning for a long time or microwaving for two minutes. You can also use chemicals, such as buried furan or spraying jinbi zhi. When encountering scale insects, spray the medicine early to prevent the spread. Jinbi zhi plus antibacterial agents works well. Secondly, is the prevention of pests on the plants. When planting succulents at home, there will always be some pests (eggs) brought in, so the plants should be taken out of the soil and the roots washed, and the soil should be disinfected before reuse. As long as the plants are healthy, a little root mealybug is not a big problem, they can be pierced to death, and if grown outdoors, you can spray the medicine freely, but the concentration should be slightly diluted in summer to prevent chemical damage from too rapid evaporation.
In daily life, to prevent hydration and black rot, first pay attention to the soil mixture, which is the premise to prevent black rot.
There are soil mixture ratios on the internet, and since China has a vast territory with different climates, I won't elaborate here. But generally, there are more granules in the south and more dust in the north. My coordinates are in northern Anhui, and the soil mixture effect is that the dry soil absorbs all the water in five seconds after watering.
Secondly, is watering, which is the most direct cause of black rot.
Watering succulent plants is a profound subject. I have summarized three points about watering in summer: do not water until dry, pay attention to temperature differences, and ventilate vigorously.
1. Do not water until dry. This does not mean that the soil should be completely dry before watering, as dry soil will cause the death of capillary roots, and watering again can easily cause mold infection and lead to black rot. My personal experience is that the top 2 centimeters of the potting soil can be watered. When watering, a small amount of antibacterial agent can be added, but the dosage and frequency must be controlled to prevent chemical damage. The amount of water should be reduced moderately compared to the amount used in spring and autumn, either watering along the edge of the pot or using purified water to soak the pot. The purpose of using purified water is to prevent the potting soil from becoming alkaline. In conditions allowing, using the sitting pot method is the best. Generally, do not take out the pot until the surface soil shows moisture. The looser and more breathable the soil, the less time is needed, because of the strong capillary action. The advantage of this watering method is that it can ensure that the upper part of the soil is relatively dry compared to the lower part, preventing root rot. Because the root tips are divided into the root cap region, growth region, growth zone, and root hair region, only the root hair region is the main part for absorbing water, with the strongest resistance to moisture, while the older roots above the root hair region have lost their water-absorbing function and mainly serve to transmit water and nutrients and for stabilization, with poor resistance to moisture, and root rot often starts here.
2. Pay attention to temperature differences. Large temperature differences give succulent plants beautiful colors, but for succulent plants that have absorbed enough water, large temperature differences are one of the main causes of hydration. Therefore, when growing succulent plants, you must always pay attention to the weather forecast, do not water two days before rain, and do not water when there is a short-term large temperature difference (whether it increases or decreases). Moderate shading is required, especially after rain. The watering time is usually in the evening, not in the morning or noon, to prevent sunburn. For those who晒肉 after rain, I can only say,新手, that's not suitable for you!
3. Pay attention to ventilation. If you want your meat to be beautiful, please expose it to the sun more; if you want your meat to survive, please ventilate more! This is related to the original ecological environment of succulent plants. South Africa and Namibia, the Canary Islands and Madeira, Madagascar Island, and Somalia and Ethiopia in East Africa, as well as Mexico in Central America, are the main producing areas of succulent plants. These places are either plateaus or islands, with cold currents nearby, making the summer cool and windy. Therefore, succulent plants in their original habitats are not as severely dormant as in our growing environment. Ventilating succulent plants in summer, especially after watering, can not only cool down but also take away the surface moisture of the pot, preventing stem black rot. Therefore, I usually water on days with wind force above level 3, and using an electric fan to blow all night is also a good effect (you can calculate the electricity bill yourself).
For plants that have started to hydrate, the hydrated leaves should be removed and discarded immediately, and ventilation should be increased. For plants with hydrated and blackened stems, the top should be cut immediately. When dealing with腐烂 plants, be sure to keep the tools clean and sterile, and wash your hands carefully before touching other plants. Use a sharp knife to cut off the infected part, as much as possible, then apply an antibacterial agent to the wound. Finally, place it in a shaded and well-ventilated area to let the wound air-dry naturally, or you can also use a small fan to blow it.
That's all my views and suggestions on hydration and black rot. If there are any mistakes, please correct me. I'm a liberal arts student, I can't afford it……
What has been introduced above is the specific introduction to the causes and solutions for the hydration and black rot problems in succulent plants. I hope you will like it!