It is not common for snake plants (mother in law’s tongue) to suffer from pests. Strong and resilient, these plants can withstand the harshest conditions and require little water. Although Sansevierias are herbaceous plants, they can be infested with insects and fungi under favorable growing conditions. The spread of pests and diseases may be facilitated by warmer and dryer air.
The first step in diagnosing a sick snake plant is identifying the exact cause. You need to look for the key symptoms that the plant is exhibiting to figure out the underlying cause. Understanding how to deal with the problem will ultimately be helpful. Discover what kinds of pests your Sansevieria might have, how to identify, treat, as well as prevent such issues in the future.
Problems with Insects
Insects are the most common cause of snake plant illnesses. Pests that affect Sansevieria species include moths (worms), spider mites, mealy bugs, and thrips. Flying insects such as moths, thrips, and male mealy bugs, as well as spider mites are so small that they can float on a strong breeze. By doing this, they can easily infest nearby plants or invade most parts of a greenhouse.
Mealybugs (Pseudococcidae)
Several houseplants, including mother in law’s tongue, are susceptible to mealybugs. They can be identified by their flat appearance and waxy layer they leave behind. The same waxy layer can hold an astonishing 50 to 100 eggs. They have a whitish body and a segmented oval shape.
Signs and Symptoms
Female mealybugs eat the sap of snake plants. The leaves develop small visible wounds while they feed. In the end, the leaves will be able to store less water as a result of this damage. Through sucking on the leaves, mealybugs make them weaker. This can even cause the leaves to fall off in its advanced stages.
The Treatment
- Handpicking and dabbing mealybugs in alcohol is an effective method if the infestation is localized and small. Alcohol can be used to kill them manually by picking them off the plant.
- The leaves can also be removed by wiping them with alcohol dipped cloths or paper towels. Cotton swabs soaked in rubbing alcohol can also be used.
- If the bugs are extremely stubborn, water spray could be used to force them out. Plants should be placed upside down outside, removed from pots and held outside. Apply some strong water to the leaves now. Several applications may be needed to remove all the bugs. Once that is done, hang the plant upside-down over night to let the water drain out. Snake plants should not be placed in direct sunlight. Repot it later in fresh soil.
- Water may not be enough to eliminate mealybugs from plant crevices if they have already laid eggs. In this case, synthetic insecticides are most effective.
Spider Mites (Tetranychidae)
Spider mites can be found on snake plants as well. Spider mites are very small (a little over 1 mm in length), live on the undersides of leaves, and can be difficult to see. When you examine the leaves closely, or shake them on a white surface, you can see small, round bugs. Spider mites come in different colors.
Signs and Symptoms
Spider mites attack snake plant leaves in a similar way to mealybugs. Plants are injured when they suck out the sap from the leaves. Plants with wounds on their leaves are more susceptible to pests. In the advanced stages of infestation, leaves will wilt and fall off. Untreated, the condition can also lead to the death of the plant.
The Treatment
- If spider mites are present on the plant, they should be washed off with plain water. Wash the leaves under the shower, wipe them carefully, or spray them with water. Completely dry the leaves of the snake plant. In order to get rid of mites, raise the humidity around the plant.
- A chemical treatment with insecticides is another possibility for killing spider mites. By penetrating into the bugs’ bodies, insecticides cause electrolyte imbalance. Ultimately, this will kill the bugs. One of the most widely available remedies for mites is insecticidal soaps.
- Instead of using insecticides, you can also use regular soap. Spray the plants with a solution of dish soap liquid and water. The soapy water suffocates the bugs, killing them as well as their eggs. Keep the plant near a draft or in an airy room to let it dry off. The process should be repeated every 5-7 days until all mites have been removed. Bug infestations can be effectively reduced using this method.
Caterpillars
The larvae of butterflies and moths are called caterpillars. They cause quite a bit of damage as well as caterpillar worms. Thus, this infestation is easily detected since it is clearly visible to the eye.
Signs and Symptoms
Caterpillars make holes along the sides of the leaves. They sometimes eat the central part of the leaf as well. When you see holes on the leaves, but no worms, it could mean the worms have already moved on. It is easy to identify old damage by its calloused appearance.
The Treatment
You can get rid of caterpillars by placing cardboard around the base of your plant.
This problem can be combated by using Bacillus thuringiensis, a naturally occurring soil bacterium. Either the caterpillars will die or they will disappear.
Thrips (Thysanoptera)
In addition to being small and thin (less than 20 microns), thrips are also a kind of spider mite. Thrips with long hair on their wings can be observed as adults. The colors of different species can be used to identify them. Yellow or light brown are the predominant colors of flower thrips. In contrast, thrips that feed mainly on leaves and are found in greenhouses are dark brown or black in color.
Sign and Symptoms
A thrips can be identified by the appearance of tiny black spots on the plant. Including leaves, stems, and buds, they can infest the entire plant. On a white surface, they are easier to identify. With a magnifying glass, you can observe the bugs as the leaves are shaken over white paper.
Plants are damaged by rips as they penetrate the cells and feed on them. You can see this damage on your snake plant by its curled or distorted leaves. If the leaves have been fed, they may develop silver-gray scars, rough patches, or callused spots. In addition to transmitting viral diseases, thorns can also cause viral infections in many indoor plants.
The Treatment
When your snake plant has been infested with thrips, the first step to treating it is to remove the infected leaves. Use a sharp knife or pruner to remove dead and damaged leaves. The leaves that have started curling but still look healthy can be kept. Carefully dispose of the removed leaves.
With a cotton ball or wet cloth, wipe off the snake plant leaves. Instead of water, you can also use rubbing alcohol. To remove tiny bugs and eggs hidden in crevices, thoroughly wipe both sides of each leaf.
The whole plant should be thrown away if the thrip infestation has spread widely. Make sure to discard the plant so that it does not cause cross-contamination and infect your other healthy plants.
Fungal Problems
There is a connection between fungal infections in Snake plants and moisture on the leaves. Wet and mushy leaves can be caused by overwatering a plant. You can also get it by spilling water on the leaves and letting it sit there. A fungal disease is more likely to affect wet leaves. It is possible for plants to become infected with fungi and eventually die. To prevent this from happening, precaution needs to be taken.
Red Leaf Spot (Fusarium Moniliforme)
Fresh leaves that are growing in the center of the plant are most affected by this infection. Snake plants are easily recognized by the red spots on their leaves as their name suggests.
Signs and Symptoms
The symptoms of red leaf spot first appear on the newest leaves within the central whorl of the plant. This rosette can only become infected when wet and spores are present. Leaves usually develop sunk lesions of irregular shapes. Lesions of this type are usually reddish-brown and have a yellow border. As a result of constantly wet leaves and severe spread conditions, the lesions coalesce and infection spreads into the stem.
The Treatment
In order to control this infection, you need to keep the foliage of the plant dry. By doing so, red leaf spot disease will no longer be present in the foliar phase.
For diminishing symptom expression, fungicides are also effective. If snake plants are treated with fungicides and the leaves are kept dry, growth can be seen in the center in the form of several new buds.
Southern Blight (Sclerotium Rolfsii)
Despite attacking all parts of a plant, this pathogen is most common on leaves. It can also affect the stem and even the soil surface.
Signs and Symptoms
Water-soaked, necrotic spots appear on leaves as the first signs of southern blight. At the soil line or near it, these lesions develop. In later stages, coarse white round mycelium grows in a fan-like pattern on the leaves or soil surface. In addition, small sclerotia appear almost anywhere on the affected part of the plant or on the soil surface. Unlike mustard seeds, these sclerotia are white and cottony. Darkening of the skin is a consequence of maturing. Their color eventually becomes dark brown as they harden. At the same time, the stem of the plant starts to wilt and rot.
All these symptoms indicate that your plant has been infected with southern blight.
The Treatment
Water or alcohol can help you remove the fungus from the plant if it is still in the early stages. As well as replacing the soil, you will need to remove the upper 1-inch layer. Keep the soil and leaves dry by reducing the amount of water.
For preventing the spread of disease, chemical control can be very effective. For dealing with this problem, there are several fungicides on the market.
By using proper watering methods, letting the water drain and maintaining a constant temperature around the plants, this disease can be prevented.
Problems caused by bacteria
Soft Rot (Erwinia Carotovora)
A snake plant can also become infected with bacteria in addition to insects and fungi. A very common problem observed during propagation by leaf cuttings is soft rot.
Signs and symptoms
Soft rot is easily recognizable by the mushy rot on the lower end of a cutting. Occasionally, the plants develop a fishy, rotten odor. Soft rot can occur when you fail to regularly change the water when propagating your plants in water.
The Treatment
Bacterial leaf spots can be controlled by removing the water on leaves. Unfortunately, most cases of this condition cannot be cured.
A bactericide’s efficacy is very poor, so it should not be used.
The best way to prevent most bacterial infections is through preventative measures. In order to control the infestation, Streptomycin sulfate solution 21.2 % (Agri-Strep) may be used. Sanitation and the use of clean cuttings are very important.
Nematodes
In soil lives a type of parasite known as nematodes, which damages roots of various plants.
Signs and Symptoms
The roots of this plant suffer from galls, which identify this disease. There may be drastic reductions in the root system in some cases. The wilting leaves and stunted growth are the symptoms of an advanced stage.
The Treatment
- This problem can be treated with nemacids.
- As nematodes damage plant roots, it is recommended to destroy nematode-infested plants completely. Despite this, snake plants can still be propagated using leaves, since they are unaffected.
- The soil should be replaced in the winter or tilled 2-3 times a year.