How to solve sooty mold? See the prevention and treatment methods here

Text

Text and images: Curator

2017 was the 5th year of growing succulents. Through all the ups and downs over the years I have gained some experience, and every year I set a small goal. This year, to get through the summer, in April to June I gave 3 doses of Huahuashen to prevent mealybugs, then full of confidence I looked forward to successfully getting through the summer, with the beautiful vision of no stretching, no spreading, and maintaining their form.

The reality is that every year getting through the summer brings me a new challenge. This year, catching me off guard, more than two thirds of the 300-plus pots of succulents on my balcony were infected with severe sooty mold.

What is sooty mold? When you find small black dots or small black spots on the leaves, that is it. This is a chronic disease. Once infected, the succulents will slowly be surrounded by black spots all the way to the base of the stem, and slowly die. It is also contagious, and the surrounding ones will slowly become infected and spread.

As shown below

Generally when summer comes, with continuous poor ventilation, dampness and mugginess, this kind of pathogen is prone to breeding. Even my succulents grown outdoors in full grit did not escape this misfortune.

Of course, large-scale infection requires the right timing, place and conditions. Let me briefly explain that my succulents' situation was like this: last year one Graptoveria that had been infected with sooty mold had a relapse this year. Because of limited space, my succulents are placed very compactly, and so the pathogen silently spread. During the summer vacation, while I was out having fun, the succulents were rained on continuously by 3 heavy rains. Under these damp and muggy half-month hotbed conditions, sooty mold spread wildly across almost the entire balcony.

As shown below

This is the Graptoveria that was the source of the disease

By the time I came back and found it, the severe ones already had it all over the stems, and the leaves were speckled and pitiful to look at. The succulents were as if dormant, no longer growing, the leaves limp and mushy, and many had fallen off.

These pots were relatively severe

There were no signs of life left

Seeing this situation, there was no point in isolating them either, my heart was broken. So the first thing I did was use the carbendazim that had been sitting unused at home to drench the roots first (I almost never use carbendazim, but succulent growers still must have it on hand). Because it was still midsummer, I only drenched with half water. Be sure not to be too aggressive, or you will cause black rot from overwatering. What I want to say here is: there are many brands of carbendazim, and I only recognize the Guoguang brand. The commonly used ones have 50%-75% active ingredient, which is enough for succulents, while some other miscellaneous brands in small bags mostly have no effect.

As shown below

The second thing: using medical alcohol, a must-have for growing succulents, at 75% purity, put into a spray bottle, and spray the exposed areas above the soil, including stems and leaves, 3 times a day. I think alcohol's sterilization and disinfection still has an effect, and at the time there was nothing else at home.

As shown below

The third thing: I knew that with such a severe situation I could not be careless. If the treatment failed, I would have passively left the hobby, instantly turning into someone selling pots at a stall... So I began looking for more effective plant antibacterial medicine. This process involved looking up information, reading posts, going to the market, searching Taobao, asking vegetable farmers, and consulting experts, and finally I settled on this liquid medicine whose name I could never remember. I bought it from Taobao, and to get free shipping I bought 20 packets...

As shown below

After it arrived, I diluted each packet with 1000 ml of water as the shop told me. Half a month after drenching with carbendazim, I drenched with half water again (again reminding you not to be aggressive, wait until the succulent's potting soil is dry before drenching, and I used the medicine on all my succulents, because those that looked fine might already be infected without showing it), and paired it with spraying the leaves and stems at least once a day. Of course, I really did not know how effective it would be, I could only use my succulents as an experiment. Illness comes like a landslide, and goes away like drawing silk; treatment needs a cycle. Sooty mold was already beyond cure. If it failed, there probably would not be extra time to try another medicine. My mood was so anxious then, so when many succulent friends kept asking me what medicine I used, I only mentioned alcohol and carbendazim.

One week after drenching with the medicine, I saw that the succulents' condition was no longer worsening, but for over half a month there was no improvement and no sign of growth. Half a month later I drenched again. By then it was already September, and the damp heat was gradually fading. After another half month, I drenched a third time. I observed that after drenching the succulents began to feel a bit firmer, and this sign gave me hope.

Compared with the same plant in the picture above, there was obvious improvement

There were signs of life in the middle of the leaves

I kept spraying medicine every day. About a week later, around the end of September, I saw signs of growth in the center of the leaves. The diseased leaves on the outer ring had mostly fallen off and been used up, and the stems were still surrounded by pathogen, but there were signs of new roots growing. I knew the succulents were undergoing a miraculous rebirth from the inside out.

Entering October, I did not give a fourth root drench of Jiejun, and instead switched to carbendazim. I worried that using medicine too aggressively would backfire, and I sprayed Jiejun on the leaves once every 2 days. By this time the succulents had clearly improved, but were still pitiful to look at... Fortunately, in the growing season with large temperature differences, the succulents also showed some color, and I could relax.

Below are all the succulents reborn after surviving the ordeal

Now I can announce the result: gratifying and worth celebrating. Although this summer sooty mold ravaged almost all my succulents, not one of them passed away. Although they were in a miserable state, after surviving the ordeal they have ascended to become gods. This summer's goal of no casualties was achieved, and next year I can set a new goal!

The picture below is the only one that recorded more than 2 months of the ordeal

This is how beautiful it looked before getting through the summer

Sooty mold begins. This was not the most severe one, a hellish trial

Slowly improving

Mid-October

This was taken last week, completely recovered

Finally, let me summarize the experience:

1. Sooty mold recurs every summer. If any plant has been infected, pay attention to it the next year.

2. If discovered early, when only the outer ring of leaves has small black dots, you can choose to immediately pull off the leaves. This can effectively block the spread of the pathogen, and isolate it.

3. If you find it has already spread to many, use medicine immediately. You can refer to my method. For mild cases, Guoguang carbendazim paired with alcohol spraying is enough.

4. If the leaves and stems are covered with black soot, it means the situation is very bad. At this time, Jiejun root drenching paired with spraying can handle it! Do not forget to wear a mask!!!

5. An important one: prevent trouble before it happens. Prevention is far easier than treating disease. Next spring, while preventing mealybugs I will also prevent sooty mold (very simple, just drench with medicine when watering: drench Huahuashen for mealybugs, and carbendazim for sooty mold). This is the most important experience I gained this summer!!!

This post is a record post, not a research academic article, and does not provide professional explanation. I believe my experience has a certain universality, and I share it with everyone.

The article was compiled by the Succulent Plant Boutique Pavilion, and the copyright belongs to the original author. For some articles the source cannot be identified, and they are marked as from the internet. If there is any infringement, please contact us immediately and we will handle it promptly.