Saving snake plants from pests!
It is usually not an issue for Snake Plants (Mother in law’s tongue) to be subject to pests, as these plants are robust and resistant to harsh weather conditions and infrequent watering. Although insect and fungal infestation are relatively rare, they can occur under favorable conditions. Warmer and dryer air may be conducive to pests and diseases.
When you notice your snake plant is sick, the first step is to identify the exact cause. To identify the underlying cause, look for the key symptoms the plant is showing. You can learn about the different types of pests that your Sansevieria may have and how to identify, treat, as well as prevent such issues in the future by reading along.
Insect Problems
Usually, snake plants contract diseases from insects. The most common pests on snake plants are moths, spider mites, mealybugs, and thrips. A moth, a thrip and a male mealy bug are flightless insects, while spider mites are so tiny they can float in a strong breeze. These insects can freely invade nearby plants as well as contaminate most of a greenhouse.
Mealybugs
Many houseplants, including mother in law’s tongue, are susceptible to mealybugs. They have an oval shape with whitish segmented soft bodies that have a flat appearance. Mealy bugs lay 50 to 100 small eggs in a waxy layer.
Symptoms
During feeding, mealybug females create small visible wounds on the leaves of the snake plant. This causes the water storing cells in the leaves to suffer, eventually causing them to store less water. By sucking on the leaves, mealybugs destroy them, leading to the leaves falling off. At an advanced stage, this can even cause them to die.
Treatment
- You can manually pick mealybugs from the plant and add alcohol to kill them if they’re only found in a small area. It’s an effective way to control them.
- You can also use rubbing alcohol and cotton swabs to clean off the leaves, or you can dip a paper towel or cloth in alcohol and wipe them off.
- In an extreme case, you can force the insects out using water spray. You will need to turn the plant upside down, remove it from the pot and spray it with relatively strong streams of water. You may need to apply more than one application of bug killer to remove all the bugs. Let the plant hang upside-down overnight to drain all the water. Place it in bright indirect sunlight. Repot the snake plant in a fresh pot.
- The mealybugs may not be able to be exterminated with water if they have laid eggs in crevices of the plant. Synthetic insecticides are best in this case.
Spider Mites
In addition, snake plants are prone to spider mite infestations. Spider mites are microscopic (about 1 mm in size), reside under leaves, and are difficult to spot. It’s possible to see round, small bugs in the leaves if you examine them closely, or shake them on a white surface. Spider mites can be different colors.
Symptoms
The leaves of snake plants are attacked by spider mites in much the same way as mealybugs. They sap the sap from the leaves and harm the plant. When leaves have wounds, the plant will be more vulnerable to pest infestations. An advanced stage of infestation will lead to leaves wilting and falling off. If the condition persists, the plant will be killed.
Treatment
- Spider mites can be removed from plants by washing them with plain water. You can wipe the leaves carefully, wash them in the shower, or spray them with water. The snake plant’s leaves should be completely dry, and then the humidity around the plant should increase because it drives off mites.
- Chemical treatments with insecticides are another option for getting rid of spider mites. Insecticides penetrate into the bugs’ bodies and cause an imbalance in their electrolytes. This ultimately kills the bugs. An insecticidal soap against mites is commonly available in stores.
- If you would rather avoid insecticides, you can make your own soapy water solution by mixing dish soap liquid with water and spraying it on the plants. Soapy water drowns the insects and kills them as well as their eggs. It is recommended that you dry off your plant by keeping it in an airy environment or in a drafty room. Repeat this process every 5-7 days until the mites are gone. This will allow you to get rid of the pest infestation.
Caterpillars
The larvae of butterflies and moths are called caterpillars. Both the caterpillars and the damage they cause are quite noticeable, so the infestation is easy to detect.
Symptoms
The worms damage the leaves by making holes along the edges. Sometimes they also eat the central part. If you see holes on the leaf but no worms, it could mean they have already gone. You can tell when the damage is old if the leaves appear calloused.
Treatment
- Caterpillars seem to be repelled by placing cardboard around the base of the plant.
- The caterpillars will either die or go away when Bacillus thuringiensis, a nontoxic, naturally occurring soil bacteria, is applied.
Thrips
Thrips are small (1/20 inch or less) and thin insects. Adults can have a long hair fringe around the margins of their wings. They correspond to different species according to their coloration. A flower thrip’s color ranges from yellow to light brown. However, thrips that mainly feed on leaves and are found in greenhouses are dark brown.
Symptoms
Thrips appear as small black spots on the plant; they can infest the entire plant, including leaves, stems, and buds. You can identify them by shaking the plant leaves over white paper and observing the insects through a magnifying glass.
In your snake plant, damage can be seen in the form of curled or distorted leaves as a result of thrips feeding on the cell wall. A thrip’s feeding activity can result in the development of silvery-gray scars, rough patches or callused areas on the foliage. A thrip can also transmit viral infections to indoor plants, like tomato spotted wilt.
Treatment
- When thrips infest your snake plant, the first step is to remove all the affected leaves. Trim off dead and damaged leaves using a sharp knife or pruner. Keep the leaves that have started curling inward, but still look healthy. Dispose of all removed leaves carefully.
- Wash out the snake plant leaves using a damp cloth or cotton ball. You can use rubbing alcohol in place of water if necessary. Make sure to wipe both sides of each leaf in order to remove bugs and eggs hidden within crevices.
- Throwing away the entire plant is safe if the thrip infestation is widespread and has affected most of your plant. Ensure that you dispose of the plant properly to prevent cross-contamination and infect your healthy plants.
Fungal Problems
Snake plants are commonly affected by fungal infections primarily due to moisture on the leaves.
In addition to overwatering, spillage of water on leaves can cause wet and mushy leaves, which are more susceptible to fungus diseases. A plant can rot from a fungus infection and die as a result. Therefore, it is imperative that precautions be taken to prevent this from happening.
Red leaf spot
The infection usually affects the fresh leaves grown in the centre. It can be identified by the presence of reddish spots on the leaves of snake plants.
Symptoms
The first symptoms of red leaf spot appear on young leaves that are in the centre of the rosette. Infection occurs when these leaves are wet and spores are present. Sunken lesions of irregular shapes are usually present on the leaves. A reddish-brown color and often a yellow border can characterize these lesions. When the diseases spread rapidly and continuously wet leaves are present, the lesions coalesce and the infection spreads into the stem.
Treatment
- In order to control this infection, it’s necessary to keep the foliage of the plant dry. This can eliminate the foliar phase of the red leaf spot disease.
- A fungicide is also effective for diminishing the severity of the symptoms in snake plants. If the disease is treated with fungicides and the leaves are kept dry, new growth may begin in the centre.
Southern Blight
Plants can be infected by this pathogen in many parts, but leaves are most commonly infected. However, it can also affect stems and even soil surfaces.
Symptoms
At first, southern blight symptoms consist of water-soaked, necrotic lesions on leaves near the soil line. Later, coarse and round mycelium develops in a fan-like pattern on leaves or soil. In addition, small white spots form on the plant or soil surface.
As they mature, these sclerotia grow darker and harder, eventually turning dark brown in color. At the same time, the stem of the plant begins to rot and wither. If all of these symptoms are present, your crop is definitely affected by southern blight.
Treatment
- If the fungus is in the initial stages, you can save the plant by wiping off the affected areas in water or alcohol, replacing the soil, and keeping the soil and leaves dry. However, if the fungus is more advanced, you’ll have to replace the entire plant.
- The addition of fungicides to the market can help control disease outbreaks. Several fungicides are available to handle this problem.
- In order to avoid this disease, it is imperative to properly water the plants, let the water drain, and maintain a temperature near the plants.
Bacterial Problems
Soft Rot
Additionally to insects and fungi, snake plants can also be susceptible to bacterial infection. Soft rot is often seen as a result of leaf cutting propagation.
Symptoms
Soft rot is usually characterized by the mushy rot at the lower end of a cutting. Sometimes the plants have a fishy, rotten smell. Soft rot can occur when you propagate a plant in water and forget to change the water regularly.
Treatment
- Getting rid of the water on leaves can prevent bacterial leaf spots, but in most cases, it is impossible to cure them.
- It is not recommended to use bactericides due to very poor effectiveness.
- Agri-Strep 21.22% may help in controlling bacterial infections. Clean cuttings and strict hygienic practices are crucial in preventing infections. An antibiotic solution of streptomycin sulfate may help in the control.
Nematode Problem
Root Knot Nematode
The roots of plants are damaged by microorganisms called nematodes, living in the soil.
Symptoms
When the disease is advanced, leaves dry up and grow stunted. The disease can be identified by galls on the roots. The root system is drastically reduced in some cases.
Treatment
- For this problem, nemacids are an effective treatment.
- Because the roots of nematode-infested plants are damaged, it is recommended to destroy them completely. However, you can still propagate snake plants using leaves, which are not affected by the nematode.
- The soil should be replaced or tilled on a regular basis in the winter months.
Weed Problem
Although the occurrence of weeds indoors or in greenhouses is very unlikely, there is still a chance. Weeds can occur through the soil, airborne seeds in the ventilation system, or water in holding ponds.
Treatment
The presence of weeds in your snake plant container is not a big deal. Just pull them out and remove them from the pot. Clean soil and good sanitation practices will help to prevent this issue in the future.
Conclusion
Plants of this species are hardy and usually resilient against disease. Snake plants can still be propagated through healthy leaves and leaf cuttings if necessary. As with any plant, it is important to take good care of your snake plants because they are less likely to succumb to pests when they are strong and healthy. Preventive measures and routine care will go a long way towards avoiding pest issues in the future.