Spider mites can be a problem for succulents even though they are more and more popular as low-maintenance plants. In fact, many people grow them as house plants. While succulents are easy to grow, they do have a few pest problems.
Spider mites make little cobwebs where the stem of the succulent meets the leaves. These are usually located on the bottom of the leaves. Spider mites are hard to see because they are tiny. Related to spiders, these mites are not killed by most pesticides. However, there are other ways to control them.
There are several types of spider mites, but they all puncture the cells of succulents and drink the juices. This leaves scars behind. A severe infestation can stunt or even kill a plant. Here is the information you need to control spider mites on succulents.
Read also: How to Care for Succulents
What Are Spider Mites
Spider mites are arachnids, related to spiders and ticks. They are small creatures with a front part that is just the mandibles and a backside that serves as both a head and abdomen. Spider mites have eight legs. They are about the size of the period at the end of a sentence. As arachnids, insecticides usually don’t kill them. There are many types of spider mites, and they infest over 200 plants. They vary in color, depending on the species and time of year. They may be brown, green, red, or yellow. In the winter, many turn red or orange. This accounts for one of their popular names, “red spiders.” Some spider mites are difficult to see without a magnifying glass or, in some cases, a microscope. Spider mites produce webbing to cover themselves and protect them from predators, hence the ‘spider’ part of their name.
Signs of Spider Mites on Succulents
Spider mites do not pierce the leaves they are feeding on, or chew on them. They use their mouthparts to puncture cells on the surface of the leaf and drink the juices this releases. They can puncture 18 to 22 cells a minute. Each time they pierce a cell, it leaves behind a wound. The plant seals the wound and a scar quickly forms. Most people first notice the spider mites because they see the tan scars on the leaves. Since each cell that is punctured is small, a bad infestation can cause the leaf to look a dappled bronze or tan. Spider mites like the tenderest tissue they can find, which usually means they infect the plant at the crown or where a leaf meets a stem. They form cobwebs on the bottom of the leaf, which is where they prefer to remain. Spider mites can stunt leaves and can even kill the plant if there are lots of them present.
Lifecycle of Spider Mites
Two-spotted spider mites (Tetranychus urticae) are the most common mite that infects succulents. The females lay their eggs in the fall on a plant. Fertilized eggs produce females, and unfertilized eggs produce males. The eggs hatch in the spring after it is warm. At this point, the larvae have three pairs of legs. After shedding their skin, they become nymphs. They then have four pairs of legs. Spider mites can go from egg to adult in as little as 1-2 weeks, depending on the temperature. Spider mites can lay many eggs and the colony can reach very high numbers in less than two weeks if the temperature is 90F or above. In fact, a single two-spotted female can produce a million mites in a month or so.
Preventing Spider Mites on Succulents
Spider mites are easier to prevent than to get rid of. Follow these tips to remain spider mite-free.
Quarantine New Succulents
Most spider mite infestations start with them riding into your house or garden on new plants. It is wise to carefully examine the plant before you bring it into your home. If you see signs of spider mites, do not buy the plant. Even if you do not see signs of a pest, it is wise to quarantine the plant for two weeks so any small mites will have time to become apparent.
Check Your Plants
You should regularly inspect your succulents every 4-5 days for pests. Take a handheld magnifying glass and inspect the bottom surface of the leaves. If you see small creatures moving around or see webbing, you probably have spider mites. Holding a piece of white paper under the plant and shaking the leaves should make the mites fall onto the paper. They then scurry to escape, and you will be able to see them.
Keep Your Succulents Healthy
Spider mites especially like plants under stress. They thrive in hot, dry conditions. Make sure your succulents get enough water. You can increase the humidity and ventilation around the succulents, and they will be less vulnerable to spider mites. Place the succulents on a tray of pebbles, then put enough water in the tray to almost cover the stones. As the water evaporates, it creates humidity and makes the plant happier. While humidity and ventilation alone will not kill the spider mites, it will help keep them from colonizing your plant again.
Getting Rid of Spider Mites from Succulents
Getting rid of spider mites is harder than it sounds. Since they are arachnids, most insecticides do not kill them. It is best to take a multi-pronged approach to remove the spider mites.
Fast Mite Removal
The fastest way to get rid of spider mites is to put your succulent in the bathtub and spray the plant with water. This is not the way you water succulents, but the spray will force the spider mites off the plant. Make sure you spray the undersides of the leaves, too. This will help remove spider mite webs, too.
Some lady beetles, minute pirate bugs, predatory thrips, big-eyed bugs, and predatory mites will eat the spider mites. This works better if you put the natural enemies on the plant before the spider mites get bad. Outside, these predators would naturally follow the spider mites, but you will have to purchase them from a landscape supply house, probably over the internet. If you spray your succulents for insects, you will kill the predators, too. You will have to tolerate a low level of spider mites all the time, so the predators do not starve. This is easier done outside than inside.
There are not many miticides that kill spider mites, and most of those are not approved for indoor use. There are some things you can use that will kill them. You can spray spider mites with insecticidal soap or neem oil. Both are organic. They do not hurt animals or people and do not cause a problem for most nontarget insects. They work by smothering the mites, so the soap or oil has to physically cover the mite for it to work. If you can move the plant, doing this in the bathtub or shower is a good idea. Neem oil stains things it gets on. Insecticidal soap will leave soap scum on whatever it touches. Before you put these products on your succulent, test them on a small part of one leaf. Some succulents will burn from them in the sun or under grow lights. If the leaf is fine in 24 hours, you will not usually have any trouble with them burning. Make sure you completely cover the tops and bottoms of the succulent leaves, especially the points where the stems meet the underside of the leaves. You may need to apply these products several times at intervals of 3 days to completely kill all the mites and their eggs. Always follow the label directions because you can hurt your succulent if you go overboard with either insecticidal soap or neem oil.
Discard The Succulent
If the succulent is badly infested, it may be better to discard the plant in the trash. Getting rid of the mites is only the first step in a long recovery for a succulent, and they will never look good from the scars on the leaves. Spider mites may spread from this succulent to other plants you have. If you discard the plant, dump it and the soil into a trash bag and seal the bag tightly. Take the bag out to your trash cans to avoid having any of the mites get out of the bag and be loose in your house.
Spider mites can be difficult to kill. They are often resistant to miticides. They often get in the house on another plant. Be sure to quarantine any new plants. Examine plants carefully before bringing them into your house. If you find spider mites on your plant, washing the plant and spraying the mites off will help. If that doesn’t get rid of them, there are other ways to treat the mites. It might be best to discard heavily infected plants, so the spider mites do not spread to your other plants.