What to Do When Lilies Grow White Bugs? Aphid Spraying and Pest and Disease Control
Among the best indoor plants, the lily is undoubtedly one of the flowers most loved by gardening enthusiasts, and many people grow it in pots at home. But if you neglect its care, or fail to follow the proper lily cultivation methods, it will become diseased and infested with pests, greatly affecting its ornamental value. So what should you do when lilies get bugs? Below is a guide to lily pest and disease control; let's take a look together.
I. When Lilies Get Bugs, Spray with Pesticide
The lily is a very beautiful flower, but for various reasons it can become infested with pests and diseased, and gardening enthusiasts must be very anxious. If not treated in time, the lily will not only lose all its ornamental value but in severe cases may even die. As for what to do when lilies get bugs, we should identify which type of bug it is and then address it accordingly. In this guide to lily pest and disease control, we will discuss pests and diseases separately.
(1) Lily Pests: Aphids / Cutworms
1. Aphids
One of the main pests of lilies, it mainly harms the tender leaves and stems of lilies. Especially when the leaves unfold, aphids will parasitize on the leaves and suck the sap. Symptoms: the plant shrinks, grows poorly, and the flower buds become deformed.
Solution: When aphid infestation is found, spray with a 1200-fold aqueous solution of dichlorvos, or kill them with tobacco leaf water: add 50 grams of tobacco leaves to 5 kg of water and boil.
2. Cutworms and Other Pests
In addition to aphids, pests such as cutworms, mole crickets, ants, and earthworms also harm the growth of lilies. They mainly gnaw on seedlings or stems, causing root rot and dead seedlings, with very serious consequences.
Solution: When the above pests are found, place tea seed cake or a small amount of tung seed cake at the base of the bulbs; in severe cases, drench the roots with a 500-600 fold dilution of dichlorvos, which is very effective against mole crickets and cutworms.
(2) Lily Pests and Diseases: 4 Diseases
Regarding lilies getting bugs, after reading the above content I believe everyone knows how to handle it! However, besides pest infestation, diseases also constantly threaten lilies, and the main lily diseases are 4 types: mosaic disease, leaf spot disease, bulb rot, and leaf blight. The specific symptoms and control methods are as follows:
1. Mosaic Disease
It is one of the main diseases of lilies, mainly harming the leaves. Symptoms: leaves become smaller, edges curl, and brown-green mottled patches and necrotic spots of varying shades appear. In addition, the lily flowers are abnormally shaped and cannot open fully.
Solution: When the above symptoms are found, gardening enthusiasts should cut off the diseased leaves of the lily and pull out the diseased plants; in severe cases, spray with 1% Bordeaux mixture.
2. Leaf Spot Disease
Another lily disease, it also attacks the leaves. Symptoms: small brown spots grow on the leaves and expand into lesions; afterward, many black dots appear in the center of the lesions; in severe cases, the entire leaf turns black and dies.
Solution: First, remove the diseased leaves; second, when the infection is severe, spray once with a 500-fold dilution of 65% zineb wettable powder to cut off the spread of the virus.
3. Bulb Rot
Bulb rot, as the name suggests, means the lily's bulb has rotted. Symptoms: brown lesions appear on the bulb, and in severe cases the entire bulb turns brown and rots.
Solution: When the above symptoms are found, they should be addressed immediately. At this point, spray with a 300-fold dilution of 65% zineb.
4. Leaf Blight
One of the main diseases of lilies. In affected plants, irregular round lesions appear on the leaves, mostly light yellow and grayish-brown in color, and in severe cases the leaves wither and die.
Solution: When this disease is found, promptly remove the diseased leaves, and at intervals of 7-10 days, spray with a 800-1000 fold dilution of 50% thiram wettable powder; 3-4 sprays will suffice.
That is all the editor has to share about lily pests and diseases. Next time you encounter the above symptoms, you should know what to do! Overall, during the growth of lilies, pests and diseases are unavoidable, so to avoid unnecessary trouble, gardening enthusiasts should remember the solutions above.
What to Do When Oriental Lilies Get Bugs: Pest and Disease Control for Oriental Lilies / Removing Bugs with a Toothpick
The Oriental lily is the queen among lilies, and because of its beautiful appearance it is welcomed and loved by a wide range of gardening enthusiasts. However, if it suffers from pests and diseases, the beauty of the Oriental lily will be gone forever, and by then gardening enthusiasts must be very anxious! So what should you do when Oriental lilies get bugs? Below are 5 pest and disease control methods for Oriental lilies; follow along with the editor to learn more.
I. When Oriental Lilies Get Bugs, Spray with Pesticide
Although common, the cultivation methods for Oriental lilies are not easy, and combined with the fact that most growers are beginners, improper care often occurs. The result is that the plant suffers, not only getting bugs but also becoming diseased, both of which severely affect its ornamental value. As for what to do when Oriental lilies get bugs, it's simple: identify which pest it is and then spray to resolve it. Let's continue reading for the specifics.
II. Pest and Disease Control for Oriental Lilies
1. Aphids
When it comes to Oriental lilies getting bugs, the first thing to consider should be aphids. Aphids are very small, mostly about 2 mm, and generally appear on tender leaves and newly grown buds, feeding on the sap in the leaves by sucking, causing the Oriental lily's leaves to turn yellow.
Solution: When there are few aphids, you can use a toothpick to pick them off and kill them; when there are many aphids, gardening enthusiasts can choose to spray alternately with a 3000-fold dilution of 40% dimethoate emulsion or a 1000-fold dilution of pyrethrin.
2. White Grubs, Cutworms
Among the pests of Oriental lilies, besides aphids, there are also underground pests such as white grubs and cutworms. They generally appear in April-May and gnaw at the root-stem area of Oriental lily seedlings, causing the seedlings to wither and die.
Solution: This kind of pest is rare indoors and generally appears in fields where they are planted in large quantities. At this point, gardening enthusiasts can do a good job of clearing ditches and draining water during the rainy season, and spray a 0.1% solution of 90% trichlorfon and malathion emulsion. Before spraying, use a bamboo stick to poke holes in the seedbed and then pour in the solution for better results.
3. Gray Mold
Besides getting bugs, under improper care Oriental lilies can also become diseased, and one of the most common diseases is gray mold. This disease often occurs when the temperature is relatively high and the humidity is also relatively high, and its range of damage is fairly broad: leaves, flowers, and stems can all be affected.
Solution: First, clean up the parts that have already been affected by the disease; then, spray some chemicals, such as metalaxyl, applying once every 5 days for 2 consecutive applications, which can effectively control the condition. Generally, after 7-10 days no more harmful symptoms will appear.
4. Root Rot
During the growth of Oriental lilies, beginners also easily encounter root rot in the plant. Symptoms: first, rot occurs at the roots of the plant. Then, because it cannot absorb water and nutrients, the entire plant may die.
Solution: When the above symptoms are found, if the condition is mild, spray with a 500-fold dilution of zineb; if the rot is severe, just throw it away.
5. Damping-Off Disease
Besides gray mold and root rot, Oriental lilies also often suffer from damping-off disease, which mainly harms the roots. Symptoms: some brown spots appear on the plant; in the most severe cases, it will gradually dry up and die.
Solution: If infected with damping-off disease, first gardening enthusiasts should disinfect the soil; then spray chemicals, such as chlorothalonil.
That is all the editor has to share about pest and disease control for Oriental lilies. I believe everyone will know what to do next time they encounter bugs or disease! Overall, Oriental lilies are not easy to grow, and a moment of carelessness may lead to pest and disease infestation, so everyone should take care in cultivation; only then will bugs not come knocking. Finally, may everyone's Oriental lilies bloom into beautiful flowers!
Succulent Plant Cultivation and Care - Pest and Disease Control
[How to Clean Up Common Mealybugs]Common mealybugs mainly attach to the underside of leaves and stems to suck on the plant, and are very easy to spot
Easily contagious; adults will crawl from one pot to another, so clean them up promptly once found
Because they are visible bugs, they are much easier to clean up: just use a toothpick or needle to deal with them
When they cluster too much, you can use a pesticide spray. The one I use very conveniently myself, "Huhuashen," is cheap and easy to use
Just dilute with water at a 1:200 ratio according to the instructions and spray; spray again once a week and basically you won't see those disgusting bugs again
Note that after spraying, be sure not to expose the plant to sunlight; place it in a shady spot for 4-5 days before moving it to a sunny place
Because if you put it in the sun right after spraying, it will accelerate water evaporation, which increases the pesticide concentration and can easily burn the plant
If there are children or pregnant women at home, or if you don't want to use chemicals, you can take the plant under running water to wash it
Or use a magnifying glass plus a needle to poke and burst them one by one! Repeatedly check, find, and remove them, and that's it
Because there are eggs, and eggs cannot be killed by pesticides; you can only wait for them to hatch into larvae and then remove them once found
[How to Clean Up Root Mealybugs]
Cleaning up root mealybugs is much more troublesome, because under normal circumstances root mealybugs are invisible
They live almost entirely in the soil, surviving by sucking nutrients from the root system, then laying eggs and hatching, making them extremely hard to find
Generally they can only be seen when repotting and changing the soil, so this requires us to do various checks and cleaning when we first buy succulents
The contagiousness of root mealybugs is also terrifying; adults will crawl out from the bottom of a pot and drill into another pot
But the most frightening thing is their eggs. When watering, they will flow out of the pot, and if they stick to the soil and then get mixed into other pots, there will soon be a collective outbreak
If not using chemicals, when root mealybugs are found during repotting, the original soil needs to be discarded immediately (or thrown outdoors to bake in the sun for a few months before being used in the yard)
Wash the plant's root system completely clean, then trim it briefly, then soak it in clean water for half an hour, then wash it again
Then let it dry for 1-2 days, and repot after it is completely dry. The original pot should also be cleaned again, preferably scrubbed 360 degrees with a brush
If you find it troublesome and want to use chemicals, currently the most effective chemicals, "Jiebizhi," "Supusha," "Bayer little green pills," and "furadan," can all kill root mealybugs, but they cannot kill the eggs. This requires continuous application. Personally, I am rather opposed to using chemicals; not only do they easily harm the plant, but they also cause secondary pollution to the soil. Everyone can weigh this for themselves~
For any kind of bug, everyone should treat it correctly and not be overly nervous or afraid
Because bugs and flowers are symbiotic~ Anyone who grows flowers knows that those outdoor-grown climbing roses and such produce several waves of bugs a year
So there is absolutely no need to be nervous; once found, first isolate it, then check what kind of bug it is, and then treat it accordingly
When I first saw these bugs I was also especially disgusted and especially afraid, and would frequently spray chemicals on everything, which ended up causing damage to large numbers of succulents
Now as I've gradually gotten used to it, it's fine; when I find bugs, I remove them with a toothpick at the first opportunity, with no pressure at all~
(Below are pictures of "root mealybugs"; everyone can use the pictures to judge whether their succulents are affected.) (Author: Ermu)
Early spring is a period of high incidence of various mealybug infestations on cacti and succulents. After cacti and succulents are damaged by mealybug piercing and sucking, spring growth is hindered, leaf (stem) color turns dark, and there may even appear patches of
adults already covered by waxy shields, which often leaves enthusiasts at a loss and with no choice but to discard them to prevent further spread of the pest. In fact, using alcohol brushing combined with repotting to deal with plants severely infested by mealybugs has an obvious effect and is simple and easy to do. The specific method is as
follows:
Medicines and Tools
Dip an oil painting brush in an appropriate amount of 75% alcohol and brush repeatedly over the areas where mealybugs are concentrated.
Principle and Advantages
75% alcohol has surface bactericidal and disinfecting effects. After treatment, its main components evaporate quickly, leaving little residue on the surface and making it unlikely to form spots that affect the plant's appearance. The oil painting brush, meanwhile, can flexibly and effectively brush away mealybugs breeding in the ridges and valleys, folds, thin bases, leaf undersides, and overlapping leaf areas of cacti and succulents.
Post-Treatment
Soak the brushed plants briefly in a 1000-fold dilution of 40% Supusha emulsifiable concentrate and then dry them (for home cultivation this step can be omitted), and place them separately. At the same time, combine this with repotting, remix the soil, and after washing the replaced pots, disinfect them with high temperature or soak them in a 0.05% potassium permanganate dilution to prevent secondary spread. During this period, strengthen management and watch out for recurrence of mealybug infestation.
It should be noted that this method is only a last-resort remedial measure. The care of cacti and succulents needs to focus on prevention, with treatment as a supplement. During early spring, strengthen ventilation and air exchange, adjust pot spacing in a timely manner, and pay close attention to the occurrence and spread of various mealybug infestations.
Reprinting welcome; please retain the original link when reprinting
Article link: How to Clean Up Root Mealybugs and Common Mealybugs
Pest and disease control for succulents is relatively easy to manage, but under long-term indoor cultivation, with high temperatures, dryness, and poor ventilation, there are also many "common pests and diseases" and "frequently occurring pests and diseases."
1. Red Spider Mites
They mainly harm succulents of the Apocynaceae, Euphorbiaceae, Asteraceae, and Liliaceae families. They suck the sap of young stems and leaves with their mouthparts; affected leaves show yellow-brown marks or wither and fall off. Such scars remain permanently. Generally, you can check whether there are spider webs on the underside of the leaves, and whether there are very small red/white/dark bugs; if there are, it is usually red spider mites.
Control methods: You can reduce and avoid spread by increasing environmental humidity, or suck and kill them with a 1000-1500 fold dilution of 40% dicofol, or abamectin.
2. Mealybugs
Their range of damage is very broad. They often harm succulents with tightly arranged leaves such as Agave and Haworthia, sucking the sap of stems and leaves, causing poor plant growth and, in severe cases, withering and death. Their peak period is earlier than that of red spider mites, and they often
already multiply in large numbers in early spring. But there is also an easy-to-control aspect to their damage, namely that they tend to concentrate only on a few plants; sometimes one plant is covered with mealybugs while a neighboring plant has not a single one.
Control methods: When there are few, you can remove them with a soft brush. In addition, you can also spray and kill them with an 800-**** fold dilution of Supusha. Mixing a certain amount of furadan into the potting soil has a preventive effect, but the efficacy lasts only 3 months.
3. Whiteflies
Their range of damage is not large; they occur more often on shrubby succulents of the Euphorbiaceae family such as Euphorbia tirucalli, Euphorbia milii, Euphorbia neriifolia, and Euphorbia lactea. They pierce and suck sap on the underside of leaves, causing leaves to turn yellow and fall off, and at the same time inducing sooty mold, with large patches of unsightly black powder on stems and leaves, directly affecting the plant's ornamental value.
Control methods: In addition to improving environmental ventilation, in the early stage of occurrence you can spray and kill them with a 1000-2000 fold dilution of 40% omethoate emulsifiable concentrate, or with a 500-fold dilution of malathion or a 1000-fold dilution of dimethoate mixed with dichlorvos. Two days after spraying, use a strong stream of water to wash away the dead bugs together with the black powder.
4. Aphids
They mostly harm succulents of the Crassulaceae and Asteraceae families, often sucking the sap of the plant's young parts, causing weakened plant growth, and their secretions also attract ant infestation.
Control methods: If there are few, you can catch and kill them manually, pinching each one you see. In the early stage of infestation, spray with a 1500-fold dilution of 80% dichlorvos emulsifiable concentrate, or you can also consider Bayer imidacloprid.
5. Fusarium Wilt
It is a bacterial disease and a major disease of succulents. It often harms succulents with tuberous stems, invading from root wounds, causing reddish-brown lesions on the tubers, and rotting and dying within a few days.
Control methods: Before potting, spray with a 1000-fold solution of 70% thiophanate wettable powder for prevention, and after it dries, apply sulfur powder for disinfection.
6. Anthracnose
It is an important disease harming succulents and is a fungal disease. It mostly occurs in hot and humid seasons, especially during the high-temperature, high-humidity plum rain season, and can also be caused by excessive application of nitrogen fertilizer. In the early stage of the disease, small brown patches appear on the leaves, which later expand into round or oval shapes. The lesions gradually dry up, and in severe cases the entire plant is affected.
Control methods: First, open windows for ventilation and reduce indoor air temperature and humidity. Then spray with a 1000-fold dilution of 70% thiophanate-methyl wettable powder, or spray 70% thiophanate-methyl, 60% anthracnose Fumei, carbendazim, etc., to prevent the disease from continuing to spread.
7. Rust Disease
It often occurs on succulents of the Euphorbiaceae family. Large rust-brown lesions appear on the epidermis of the stems and expand upward from the stem base; in severe cases the stems are covered with lesions.
Control methods: Combined with pruning, cut off the diseased branches and let them sprout new branches again, then spray with a 2000-3000 fold dilution of 12.5% diniconazole wettable powder.
8. Physiological Diseases
Due to harsh growing environments, such as strong sunlight exposure, severely insufficient light, sudden low temperatures, and long-term water shortage, the epidermis of stems and leaves may be scorched, turn brown, growth points may become leggy, some tissues may be frostbitten, and the tips may shrink. The most fundamental measure is to start by improving the cultivation conditions.
Pest and disease control for succulents should focus mainly on prevention. First, the environment must be clean. Strictly screen incoming succulents and only place them in the greenhouse after confirming there are no pests or diseases. Seasonal transitions are times when pests and diseases easily occur. Generally, when the
weather goes "from cold to warm" and "from hot to cool" is precisely the period when pests and diseases are most likely to suddenly break out. In addition, just after summer, succulents have just passed their long dormant period and are gradually resuming growth, but their physiological func-
-tions have not fully recovered, and their resistance is still at a very weak stage, so they are also easily invaded by pests and diseases.
Concentrated pesticide spraying in the greenhouse during the three periods of early winter, early spring, and before the plum rain season achieves twice the result with half the effort. In addition, disinfecting the potting soil has a very good preventive effect.
The chemicals commonly used for succulents mainly include two categories: fungicides for preventing and treating diseases (such as carbendazim, thiophanate, chlorothalonil, zineb, etc.) and insecticides (such as omethoate, dicofol, malathion, fenvalerate, abamectin, etc.)
. The concentration of chemicals must be strictly controlled according to the instructions, especially insecticides; even a slightly stronger concentration will cause pesticide damage, and succulents such as Obregonia denegrii and some Euphorbiaceae species are especially sensitive to this.
Regarding some of the chemicals listed in this article, some are relatively early-stage chemicals, and their current effectiveness and ease of purchase may not be as good or convenient as some newer chemicals. Therefore, there is no need to pay too much attention to the names of the chemicals; you only need to know
For the specific pests and diseases affecting your own succulents, you can search some forums for effective pesticides, or just search for that disease on Taobao, where you will usually find a whole bunch of corresponding pesticides, and buying them is very convenient.
After using the same pesticide twice, switch to a different one. Long-term use of a single pesticide easily breeds resistance.
Finally, wishing everyone's succulents to be full of vitality.
Another major disease of Sedum in summer ---- sooty mold: sooty mold, also known as sooty blotch, is one of the common diseases of plants. It mainly damages leaves and leaf stalks, and in severe cases also harms the main stem. When the disease strikes, dark brown
mildew spots first appear on the leaf surface, then gradually expand, covering the entire leaf or most of the leaf surface with black soot-like material. The soot layer is easy to peel off, covering the surface of the feather-like leaves, the leaf rachis and the leaf stalk with a layer of soot-like material, which is the mycelium and fruiting bodies of the pathogen. Leaves
completely covered by soot turn yellow because photosynthesis is affected, and eventually the whole plant withers and dies.
Symptoms of sooty mold: it mostly occurs on the surface layer of plant leaves, appearing as brown, gray, or black small mildew spots. (As shown in the picture below)
Pathogen of sooty mold: mostly caused by epiphytic fungi (multiple species).
Causes of sooty mold: besides infection from stuffy, humid soil and water in summer, it comes more from infection carried by various insects. Aphids, scale insects, ants and others, besides gnawing and sucking the sap from plant leaves and roots, also secrete honeydew and excrete feces. These secretions carry various fungi, and after being bitten by these pests, the infection worsens.
Prevention and control methods: you must strengthen pest control in daily care. Most pests break out in summer, and since most Sedum are dormant in summer, high temperature and high humidity are more conducive to the spread of fungi and outbreaks of insects. Pests and pathogens interact with each other, and can easily kill your little succulents.
You can add a certain dose of fungicide to the insecticide, once a week, or spray the fungicide three days after pest control.
There are many usable products, and most fungicides have some effect.
Ammonium diethyldithiocarbamate, carbendazim (above 5% concentration, you can use a high-concentration stock solution, diluted with more water), Bordeaux mixture and other fungal products, and thiophanate-methyl are also effective.
One thing is very important: not all brands of products containing the above ingredients are effective. Domestic horticultural pesticide management is very chaotic, and many products are reduced to placebos with no actual effect, or no obvious effect. Try to buy big brands or buy from agricultural supply stores, and the effect will be better.
Pay more attention to pest control in daily care; this disease is largely related to pest damage.
Of course, ventilation and cooling of the environment are also crucial. (Author: Qiuyang)
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Article link: Pest and Disease Control for Sedum in Summer: Sooty Mold
Since summer began, flower lovers' succulents have more or less died of black rot, and quite a few flower lovers have asked whether there is a specific cure for black rot. My greenhouse also recently suffered pest damage (mealybugs, root mealybugs) and fungal damage (black rot), so I consulted the "experts" at the Institute of Plant Protection of the Academy of Agricultural Sciences, the Institute of Vegetables, and the Institute of Medicinal Plants of the Chinese Academy of Medical Sciences, and invited one of them to the site. They all said there is no specific cure for black rot.
Black rot is mostly caused by saprophytic fungi. It occurs mostly in summer when succulents are dormant and their resistance is low at high temperatures. At present, there is no specific cure for this problem. Black rot does not only occur in succulents; it can also occur in other animals and plants. It is just like how food easily molds in summer and animal wounds easily become infected.
As for black rot in succulents in summer, greenhouses from Europe and America to Japan and South Korea also have no special treatment method (I have personally visited and consulted several bases). The more advanced ones use water curtains or industrial exhaust fans to cool down, and targetedly spray several fungicides (sealed fumigation after cooling). Small greenhouse owners just run fans and spray broad-spectrum antibacterial drugs. But
no matter which method is used, casualties are still inevitable; it is only a difference of more or less. Of course, this is not to say the drugs are completely ineffective, only that for black rot (because there are many pathogens), the effect is not obvious. For example, before you spray,
out of 1000 plants perhaps 50 may die; after spraying, 45 die. And this ratio, applied to ordinary people's home succulents, can be ignored. Moreover, if you use ventilation and cooling methods, the effect obtained is clearly
better than spraying, so rather than spending money on drugs whose effect is unknown, you might as well run the fan more.
Of course, I still got a bunch of drugs from the laboratory. They also said that many scale insect drugs have obvious effects (when there are no children or pets at home, you can buy some agricultural drugs and use them carefully). Regarding black rot, they only gave me some relatively professional broad-spectrum drugs. They especially instructed that the key to preventing and treating black rot in summer is ventilation and cooling, and pest prevention (summer is also the outbreak period for scale insects, and much black rot is the result of the interaction between scale insects and ants ---- sooty mold, because plants with wounds are more easily infected.
Someone also asked about whether black rot is contagious. First, black rot is contagious, but that does not mean it will definitely spread. It depends on the individual plant's resistance. This is also why sometimes, among plants in a group pot, A has already rotted away, while B is still alive and well, and yet C, far away from them, has also rotted.
In summary, black rot in succulents in summer is a law of nature, survival of the fittest. Death is inevitable. When growing succulents at home, everyone will more or less bring in insects (eggs). Be diligent, wash the roots and check carefully before potting, and when potting you can spray
some drugs (many agricultural drugs on the market are effective against scale insects, such as chlorpyrifos, etc.; please use them carefully), and in summer provide more ventilation and cooling. This will reduce black rot to the greatest extent. If they still die, then there is no way: ) When growing flowers, there is no such thing as never having
any die.
About scale insect drugs: the very cheap chlorpyrifos has a notable effect on scale insects, and there are many others, including Jiebijie which is also very effective after adding some surfactants. Many horticultural drugs are of poor quality; some are placebos,
and some, although effective, have no obvious effect due to issues with ingredients and additives. You can try adding some activators yourself; agricultural supply stores generally have them. (But there is no need, because it is troublesome and the direct insecticidal drugs themselves are very
cheap.)
For those that have already developed black rot but have not completely rotted away, you can use a disinfected blade to dig out as much of the rotten part as possible. It is best to also dig out some of the non-rotted part, because it is possible you cannot tell whether it is infected with the pathogen or not.
Postscript: to avoid trouble, I am only telling everyone what I know, and this does not represent authority. Whether the "experts" are expert or not, we cannot say carelessly, because the word "expert" has already become pejorative. I can only say that the people I found are relatively authoritative in the industry. (Author: Qiuyang)
Reprinting is welcome; please keep the original link when reprinting.
Article link: Summer, Some Suggestions on Black Rot
For ordinary gardening enthusiasts, the most commonly used flower medicines are nothing more than broad-spectrum fungicides such as carbendazim, thiophanate-methyl, and chlorothalonil, as well as expired pesticides such as carbofuran (carbofuran, due to its high toxicity and high residues,
has been listed by the state as a banned pesticide). For home cultivation, the above several drugs are already enough to deal with common pests and diseases, but which drug to use specifically and how to use it has other subtleties.
Generally, common diseases of horticultural plants include leaf rot, root rot, and a series of harms caused by fungal infection. If each symptom is not treated in time, it will lead to rot of some plant organs or even death of the whole plant.
However, for succulents, bacterial leaf rot and root rot rarely occur (except when wounds from physical damage are not treated in time). The only thing that poses the greatest threat to succulents is infection caused by fungi, specifically manifested as
large-scale fungal infection after poor ventilation, humidity, and poor disinfection of the growing medium, which is what we usually call "growing fuzz." The probability of outbreak is highest especially at the seedling stage. If a disease really breaks out, you can also refer to pest and disease control for succulents.
What needs to be explained here is: the "fuzz" on the soil surface is fungal infection, a pathological appearance, while the mycelium inside the medium is an inevitable phenomenon of soil organic matter decomposition, a normal phenomenon. Fungal infection
uses the plant's tissue cells as a source of nutrients, ultimately causing the plant's tissues to rot. The mycelium inside the medium, however, is a saprophytic fungus, and also a probiotic that decomposes organic matter in the medium to help plants absorb it, and will not harm plants with
vitality. (Except for the heat produced during bacterial reproduction.) These two need to be treated differently, and must not be lumped together.
Through the above analysis, we also need to be selective in using antibacterial drugs. We all know that carbendazim and thiophanate-methyl are broad-spectrum antibacterial drugs, mainly targeting bacterial infections. Chlorothalonil,
on the other hand, mainly targets the elimination of fungi. In the process of home cultivation of succulents, since the main task is resisting fungal infection, preventive application should use chlorothalonil as the main drug. To avoid the development of resistance, you can alternately
use carbendazim and thiophanate-methyl in combination at intervals. For wound treatment after pruning and shaping, however, carbendazim and thiophanate-methyl should be the main ones, and the effect of chlorothalonil will be much worse by comparison. Drug use should keep in mind the 16-character formula: "prevention first, alternate use, increase concentration, reduce frequency."
Prevention first means taking precautions before trouble starts, controlling it before signs appear, and not waiting until you see disease before using drugs. By then, even if it is controlled, it will affect the plant's appearance and even its future health. Generally, the period when seasons change is the key point for preventive application.
Alternate use means preventing fungi from developing resistance. The same drug should be used continuously at most 3 times, and then you should switch to another. Otherwise, once resistance develops, spraying is like watering, with no effect at all. And because you have one less replaceable drug, the use frequency of other drugs will increase, causing those other drugs to also become ineffective due to resistance.
Increase concentration: this is a medication strategy common to both animals and plants. For routine diseases and explosive acute infections, increasing the concentration by 30-50% above the concentration on the instructions can achieve good results in a short time, allowing the infected individual, in the sterile environment created by the high-concentration drug, to improve its own resistance through strengthened management and follow-up care and recover health early.
Reduce frequency: this is relative to increasing concentration. As said above, there are probiotics in the soil. While treating, sterilizing drugs will also indiscriminately
kill probiotics. And probiotics are beneficial for improving soil quality and preventing compaction. Therefore, drug use must take this factor into account, and drugs should not be used too frequently. Probiotics should be given appropriate room to grow. In addition, reducing the frequency of
drug use can also avoid the development of resistance. It is recommended that the interval for preventive application be 2 months, and it can be appropriately increased during the change of seasons.
Finally, two small tips:
1. After sowing, if there is continuous rainy weather and the potting soil is too wet, fungi can easily break out in the pot, and at this time medication must be given. However, since the potting soil is already in a very wet state, carrying out conventional spraying will undoubtedly add more water to the already humid environment, which is very unfavorable for seed germination. At this time, you can directly and evenly sprinkle the dry powder of the drug on the pot surface, without needing to dilute it with water and spray it.
2. Conventional sterilizing drugs are powders that use talc as a carrier (the white powder we see is actually talc, and the actual medicinal ingredients cannot be seen). After dilution and spraying, they will form white spots on the plant surface, affecting the plant's appearance and photosynthesis, and are very difficult to remove. It is recommended that after mixing and diluting the drug, let it stand for 2 hours, and after the talc settles, use only the supernatant for spraying (that is, the active ingredients of the drug), which can avoid the above contamination.
Reprinting is welcome; please keep the original link when reprinting.
Article link: Pest and Disease Control for Succulents (reprinted from Hua Jian Xiao Lan's blog)