How to Get Rid of Spider Mites on Houseplants
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Spider mites love to live on houseplants, including tropical houseplants even though they hate the humidity that tropicals thrive in, but love warmer temperatures in the 80 degree range. This is because it has been seen that the warmer temperatures help them reproduce. And when they reproduce, they do it in mass.
Each female can lay up to 100 eggs and they do this on the underside of the plant’s leaf making it hard to detect. That’s why infestations sometimes seem to appear overnight. When you find an infestation on your houseplants, you may have noticed that an insecticide is not a very effective treatment method. This is because spider mites are part of the Arachnida family like spiders and ticks, they’re not insects.
In fact sometimes when broad spectrum insecticides are used they can cause spider mite outbreaks, which could be a result of the reduction of predators which happen to be insects. In addition, these pests are known to develop resistances to toxins and pesticides which you can read about here at the University of Utah, and here where the University of Michigan shares the more treatments they’re exposed to, the more likely they are to become resistant.
Unlike larger arachnids that drink blood, spider mites drink the sap from the plants by sucking it out of the plant’s cells directly. This causes the plants to discolor sometimes turning a silver or bronze color at first, then wilting, and eventually the plant dies.
So what can you do to get rid of a spider mite infestation on your houseplants? Simple, first you want to identify that it is a spider mite and not an insect, then change the environment so they cannot thrive. Below you’ll learn how to do both.
Pro-tip: If you’re looking for an outdoor plant treatment, introducing predators like lady bugs and minute pirate bugs can be a good solution and potentially helpful for other plants in your garden.
Table of Contents
How to Identify a Spider Mite
The infestation will have silk like webbing across the plant, not the cotton-like masses from Mealybugs. Then run a white paper test.
White Paper Tests
Take a sheet of white printer paper and hold it steady under the section of the plant where you found the Spider Mite nest. Gently shake the plant while keeping the paper steady and look for tiny dots to fall. If you see small dots moving around, those are likely spider mites. You may need a magnifying glass as they are tiny, so have one handy before trying this.
Spider Mite characteristics include:
8 legs
Shaped like a spider
1/20 of an inch long (.5mm)
Red, yellow, green, and brown coloring
Ways to Get Rid of a Spider Mite Infestation
There are a few ways to get rid of Spider Mite infestations on houseplants including:
Wiping them off then spraying the plant down
Neem or horticulture oil
Rubbing alcohol
The very first thing to do is isolate the plant with the infestation so it has less of a chance to spread to other plants. If the infestation is only on a specific section of a plant like a few leaves, you may want to prune them and throw them out. Next try these three methods.
Wiping Them Off
Believe it or not, you may be able to treat a Spider Mite infestation on your houseplants by wiping them off and rinsing the plant.
Take a clean cloth and dampen it.
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Now wipe up all of the silky webs making sure to get the top and underside of the leaves, the stems, and anywhere else.
Clean the cloth very well or throw it out, do not leave it near the plants as there could be Spider Mites on it.
Take the plant to a sink with a medium-strong spray setting or your outside hose spigot and thoroughly rinse the plant making sure to get the stems, undersides of leaves, and anywhere else Spider Mites may be hiding.
Neem or Horticulture Oil
Neem and horticulture oils kill Spider Mites at all stages of their lives by suffocating them and neem oil in particular has azadirachtin. If azadirachtin is ingested by the Spider Mites can make the plants taste bad to the point where they may starve to death, it can prevent nymphs from molting and becoming mature, and cause adult females to become infertile.
Wipe any nests and webs you find with a damp cloth and throw the cloth away or wash it thoroughly.
Mix the oil with water following the instructions (normally a 1 part to 1 part ratio) you find on the bottle and spray the entire plant weekly for three to four weeks or until you no longer see spider mites.
Rubbing Alcohol
Rubbing alcohol can kill Spider Mites by dehydrating them through a process called desiccation. Once the rubbing alcohol makes contact it immediately starts to kill the Spider Mite making it a very effective and affordable way to treat an infestation.
Rubbing alcohol can also have a negative impact on plants, so spot test it by dabbing some with a cotton swab on the tip of a leaf before using this method.
Mix one part rubbing alcohol to four parts water and put in a spray bottle.
Wipe the plant down with a damp cloth and throw the cloth away or wash it thoroughly.
Spray any infestation you find including on the top of leaves, stems, the underside, and repeat once a week until the infestation is gone.
Changing the atmosphere of your home is a bit extreme when there are easier ways to kill Spider Mite infestations including wiping them off, or using horticultural oils. The three techniques above should be enough to help you get your plants back to healthy and free of Spider Mites.
