Learning how to get rid of spider mites on indoor plants is simple as long as you understand a little about their habits, preferences, and life cycle. In general, there are myriad kinds of mites—most of which we barely notice. Some live on certain types of trees. Some go for grass. (There are even mites which live in human hair follicles!). Of course, there are a few types of spider mites which gravitate to our cultivated vegetable plants like beans, peas, and cucumbers. And, unfortunately, spider mites can find their way indoors to infest our houseplants, too. In particular, it’s important to know how to get rid of spider mites on indoor plants since these teensy troublemakers can do substantial damage in just a short time.
What are spider mites?
Although they damage plants like many insect pests do, spider mites aren’t bugs. They’re actually a type of arachnid, related to larger spiders and ticks. They’re so small that you need a strong magnifying glass or macro lens to be able to make them out, and, even then, they just look like oval-shaped dots.
Like their larger cousins, spider mites do make webs, but they don’t use them to catch prey. Strewn along plant stems and underneath leaves, this fine webbing might be the first sign of spider mites that you notice.
Ideal conditions for spider mite problems
Spider mites prefer hot, dry conditions. They’re also more likely to thrive if your houseplants are crowded closely together. Under these circumstances, mites easily can crawl from one infested plant’s branches onto the plant foliage of a healthy, nearby neighbor. They’ll also travel from plant to plant via their silky webs. The delicate strands are so feather-light that they easily sail on the wind outside—or air currents moving indoors.
And, at least inadvertently, you can help spider mites get from place to place as well. They can hitch a ride on clothing, gardening gloves, and tools, so, failing to practice good gardening hygiene when working with your indoor plants can also give spider mites a leg up. (Or, perhaps, eight legs up?)
Signs of a spider mite problem on a houseplant
To understand how to get rid of spider mites on indoor plants, you need to be able to spot the signs of a spider mite activity. Because they’re so small, you’ll probably see evidence of their presence long before an infestation becomes large enough that you see actual masses of the tiny spider mites themselves.
If you have a spider mite infestation, at first, you’ll notice pale markings between the leaf veins. Eventually, some of the leaves on the affected plant may begin to turn yellow and curl. If allowed to progress, spider mite damage eventually causes entire leaves to turn brown and die.
How spider mites damage indoor plants
We’re all painfully familiar with mosquitoes which pierce our skin and feed on our most precious fluids. Similarly, spider mites pierce plant leaves and suck out the valuable green chlorophyll contained within. This results in a series of tiny white dots on the affected leaf. As this feeding continues, plant leaves turn yellow, then brown, and then they die back altogether.
Spider mites do their work from below—along stems and on the underside of leaves. They also reproduce from these vantage points. Adult femaleslay minuscule, pearly eggs which hatch out to reveal tiny, six-legged larvae. The larval spider mites then go through a couple of nymph stages which culminate in eight-legged spider mite adults. Under favorable conditions, this whole process can take just one week. The speed with which they can multiply makes it extra important to find out how to get rid of spider mites on indoor plants.
How to physically remove spider mites from houseplants
Wondering how to get rid of spider mites on indoor plants if these tiny arachnids can barely be seen with the naked eye? You can use mechanical methods to physically remove spider mites.
First, if outdoor temperatures will allow it, take the affected plant outside and spray it off with your garden hose. (Adjust the nozzle on the hose so that you can hit plant leaves with a fine stream of water, taking care not to damage your houseplant as you do this.) Otherwise, rinse off plant leaves in the shower. Do your best to reach the underside of leaves while you’re at it. Follow up by using a soft cloth to wipe off individual leaves—tops and bottoms.
For indoor plants which are too large to move, you’ll have to skip spraying them with a stream of water and instead use a wet cloth to remove spider mites from leaves and stems. Really intractable infestations may call for something stronger than water. In such cases, you can douse your cloth with a one-to-one isopropyl alcohol and water solution which kills mites on contact. A one-to-one mixture of rubbing alcohol and water will also do the job.
Using natural predators to get rid of spider mites on indoor plants
If you prefer to garden as naturally as possible, then you’ll need to know how to get rid of spider mites on indoor plants without drenching your household—and your pets—with insecticide in the process. Spider mites do have natural predators which you can enlist in the fight. Ladybugs, lacewing eggs, and other beneficial insects are commercially available and can be used indoors.
However, if you’d prefer to bring a less obtrusive biological control into your home, minuscule predatory mites are your best bet. Just as small as the spider mites themselves, predatory mites eat spider mite eggs, nymphs, larvae, and adults. They can be purchased in a granular carrier product that is sprinkled on the infested plant, or in a sachet that is hung in the branches of the plant.
How to get rid of spider mites on indoor plants with organic pesticides
Figuring out how to get rid of spider mites on indoor plants will take on more urgency if the infestation is large. In these cases, you may need to turn to a pesticide for help. (Just bear in mind that if you are using predatory mites or other beneficial insects, both chemical and organic pesticides will kill them indiscriminately.)
There are a couple of reasons to opt for organic instead of chemical pesticides. Some chemical pesticides have been shown to be harmful to human health. What’s more, spider mites have demonstrated a knack for becoming resistant to certain chemical pesticides over time. Fortunately, many organic methods are safe and effective.
Consider, for example, insecticidal soaps. These work when sprayed onto mite-infested leaves. As they make contact with spider mites, these soapy preparations coat their soft bodies. The spider mites subsequently smother and dry out. Eliminating heavy infestations may require multiple insecticidal soap treatments over a period of many weeks.
Using botanical oils for indoor spider mite control
Applying horticultural oil directly to an infested plant is another way to control spider mites. Horticultural oils are typically mineral oil-based; however, botanically-derived oils like neem oil and rosemary oil are also available and function similarly.
You may already use neem oil to combat mealybugs, aphids, and other soft-bodied pests. Derived from neem trees, it also works on spider mites by drying out the adults and smothering their eggs before they’re able to hatch.
And, for its part, rosemary oil has been shown to be very effective against spider mites. It contains natural compounds which mechanically disrupt adult spider mite functions on a cellular level. As a result, spider mites coming into contact with the rosemary oil become dehydrated. The oil also inhibits spider mite eggs’ ability to hatch. Rosemary oil is available in pre-mixed sprays as well as a concentrated powder which you can mix with water and add to your own spray bottle when needed.
To successfully treat them, you may need to spray spider mite-infested plants every few days at first. When applying botanical oils to an infested plant, pay close attention to the undersides of the leaves and the plant stem. Also, use caution when coating your plants with these products. If you do so while your plants are in direct sunlight or under bright grow lights, you could scorch their leaves. Check your individual product label for more specific instructions.
What about systemic pesticides for spider mites on houseplants?
Systemic pesticides don’t simply coat a plant’s exterior. Rather, they are actively taken up by the plant internally. Depending on the pesticide used, this may make some—or even all—of the plant poisonous to spider mites. But systemic pesticides also kill beneficial organisms which may be present, including those “good guy” predatory mites. Because systemic pesticides can even affect plant nectar and pollen, they can potentially harm important pollinating insects as well.
How to prevent spider mites on indoor plants in the future
Because spider mites like warm, dry environs, using a plant humidifier to increase the humidity levels around your houseplants is one way to help prevent future spider mite infestations. Prefer the low-tech route? You can raise humidity levels with a pebble tray instead. Just fill a saucer or tray with pebbles, add water, and place your plant’s pot on top so that it’s situated just above the water level. In time, the water will evaporate, boosting the humidity in the immediate vicinity as it does.
Good night, Mites
Remember, because spider mites are so small, spotting the damage they cause—and catching it early—is your best hope for keeping these pests in check. Spider mites suck the chlorophyll right out of plant tissues, leaving stippled, yellowing, and curled leaves behind. (They also craft very fine webbing—another important clue.) Spider mites can move from one plant to another and they can reproduce incredibly quickly.
You can knock down their numbers with physical removal methods like rinsing and wiping off leaves; introducing natural predators; or using organic pesticides such as insecticidal soaps or botanical oils. And, now that you know how to get rid of spider mites on indoor plants, you should also be able to keep them away for good. Increasing the humidity around your houseplants and giving each of them more personal space will help to make conditions less favorable for spider mites and should make future infestations less likely.
For more on growing beautiful houseplants, please visit the following posts:
- Common houseplant pests
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- Growing Venus fly traps
- Kangaroo fern how-to
- Houseplants for north-facing windows
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