As an indoor plant enthusiast, there are few things I detest more than the sight of spider mites on houseplants. If you’re anything like me, you do too. And the worst part is that they are not visible to the naked eye unless they already in large numbers.
Lucky for us, there are several tactics we can use to get rid of spider mites on houseplants quite effectively. In today’s post, I’ll several of these tactics and remedies that I have found to work fast.
You’re also going to learn some of the environmental conditions that favor the spider mites, plant damage, and the areas of the plant often infested – so that you can identify them in good time and take the necessary control measures.
Alright, let’s get started:
Fact Sheet: Houseplant Spider Mites
Botanical name: Tetranychus urticae
Life Cycle: Eggs to adult in two weeks
Common spider mites on houseplants: Two Spotted Spider Mites
Infested Areas: Mostly the underside of the leaves near the base of leaf veins.
Season Active: When the weather is hot and dry, they go dormant during the winter.
Plant damage: Yellowing of the leaves, wilting, leaf drop, and in time may kill the plant if not treated.
Appearance: Tiny eight-legged, spider-like mite, straw-colored, oval body, often with two dark blotches on the body.
Size: Very tiny, looks like moving dots to the naked eye, to see them use a magnifying glass, their web is visible to the naked eye.
Ever had of the saying that you should always focus on the things under your control? Well, you can easily control the microclimate around your houseplants. As long as you have an idea of what conditions to modify so that the spider mites find it difficult to thrive.
For starters, spider mites thrive in warm or hot, dry environments with low humidity levels. Since you don’t have any control over the fact that your houseplants are susceptible and that the mites exist in our environment, you can ensure your plants are well watered so that you keep mites at bay.
How to Get Rid of Spider Mites on Houseplants
1. Wash with a vigorous jet of water
You can adequately control light to moderate infestations, at least in part, by washing the plant periodically with a vigorous jet of water or rinsing the plants in the sink with lukewarm water. This is particularly effective for spider mites and aphids, which are most readily dislodged.
Rinsing the plant’s foliage in a sink or forceful spray of lukewarm water can help reduce the spider mite population but only if done repeatedly. For instance, you can do this every 1-2 weeks while paying particular attention to the underside of all leaves.
When you’re rinsing your houseplants in the sink, you should wrap a plastic bag around the pot and soil to prevent soil from spilling out and clogging the drain.
2. Sanitation – discard adversely infested plants
Under severe infestation, it’s always a good idea to discard the plants altogether. This is because those specific plants may be too damaged to survive or will usually require lengthy and extraordinary efforts to control the pests.
Besides, keeping those heavily infested plants will only serve as a source for infesting other houseplants. Once you’ve identified which plants to discard, place a plastic bag over the plant to help prevent any spider mites from migrating to other houseplants.
For those plants that you choose to keep, make sure to clean around them by picking any fallen leaves and throwing them away.
3. Use predatory mites (biological control)
This happens to be one of my favorite ways especially if you have a lot of houseplants infested. There are several predatory mites available commercially such as Phytoseiulus mite - Phytoseilus persimilus (most popular) and Western predatory mites – Galendromus occidentalis.
These predatory mites are about the same size as plant-feeding mites but have longer legs and are more active. They’re also more teardrop-shaped than spider mites.
If you treat your plants with predatory mites, make sure you create a conducive environment for them to remain active. Predatory mites prefer cool and humid conditions which is the opposite of what two-spotted mites prefer.
If you do it properly, these natural enemies of houseplant pests will be very effective in reducing the mite problem to acceptable levels. A good guideline is that one predator is needed for every 10 spider mites to provide control.
You need more than one application of predatory mites if you want to reduce pest populations rapidly. To apply the good bugs, concentrate releases in hot spots where spider mite numbers are highest. Once established on perennials, predatory mites may reproduce and provide biological control indefinitely without further intervention unless you apply nonselective insecticides that kill the predators.
Here’s a list of the plants that attract beneficial bugs to your garden.
4. Spray Insecticides (insecticidal soaps, neem, or horticultural oils)
You should strive to avoid insecticidal sprays as much as possible. But sometimes it’s a necessary evil especially when the infestation is high and you have to save your plants. Before you begin to apply insecticides, take your houseplants outdoors to a shaded location and then spray them. Allow sprays to dry thoroughly before returning the plants indoors.
While most chemicals are effective in controlling mites, some are better than others. Insecticidal soaps for instance are quite effective in controlling many houseplant insects and spider mites. Other great alternatives include horticultural oils that smother the mites and neem oil.
Notes on using pesticides:
Follow the cautions listed below when using pesticides on houseplants to avoid exposure and plant injury.
1. Only use pesticides that are specifically labeled for use on houseplants. Most yard and garden pesticides do not allow this use.
2. If possible, take the plant outdoors before spraying to minimize pesticide exposure within the home.
3. When using aerosol sprays, do not apply closer than 18 inches to the plant or injury may occur from the spray. This precaution appears on most label use directions.
4. Avoid treating plants that suffer from environmental stresses such as temperature extremes or drought to minimize potential plant injury.
5. If granules or plant stakes containing DiSyston are used, use extra care when watering. Excess water may carry this insecticide as it puddles or drips. This product is extremely toxic.
6. Always read and follow instructions on the label!
5. Increase the relative humidity around the houseplants
As you’ve read, mites prefer a hot and dry environment to survive and thrive. Therefore, one of the easiest ways to control them is altering the environment by keeping the soil moist but not overly saturated. A good rule of thumb is to water your houseplants when the top half-inch of soil is dry.
You can also increase the humidity around your plants by resting plant pots on pebble-and-water-filled trays, by daily misting, or by other means. However, whatever you do, take care not to overwater your plants in an attempt to increase the relative humidity.
6. Properly inspect all houseplants before you purchase them
Infestations of most insects are almost always established from infested plants recently purchased or received as gifts.
To avoid this from happening to you, inspect all houseplants before you purchase, or even they are given to you as gifts. Now, next time you go to a garden center, make sure that you carry a magnifying glass with you – it will save you a lot of trouble.
7. Isolate newly acquired houseplants or those from outdoor
If you have to buy plants and you’re not sure of their health status, the best course of action is to isolate or quarantine them for some time. As a general rule, all new plants should not be placed with existing houseplants for at least three weeks. A careful inspection at the end of this time will help determine the presence or absence of pests.
Furthermore, you shouldn’t move plants inside from outdoors. If you must move plants indoors, they should be quarantined in a spare bedroom and kept isolated from other indoor plants for about a month. During this time, regularly inspect the quarantined plants for pest problems.
Treat pest problems as necessary and continue isolation until the plants are “clean” for at least one full month before integrating them with the rest of your plant collection.
8. Keep your houseplants healthy at all times
Prevention is better than cure, which means, plants that are not vigorously growing and/or are under stress may be particularly susceptible to insect and mite injuries. For this reason, keep your houseplants healthy with proper water, nutrition, and growing conditions.
Strong plants growing in good conditions will tolerate damage more easily than weak or unhealthy plants. Besides, most insects will sense a weak plant and attack it in a few weeks.
9. Rub them away
At the initial stages, while the mite infestation is still low, you can manually rub them away from the plant. This will dislodge their web and the mites won’t survive the impact.
Remember to first wear your garden gloves beforehand to avoid unnecessary injuries.
You can do this especially for young plants which are sensitive to other control measures like high-pressure washing (hosing).
Congratulations for reading up to this point! You now have nine tactics to get rid of spider mites on houseplants. You’ve also learned some of the environmental conditions that favor the spider mites, plant damage, and the areas of the plant often infested – so that you can identify them in good time and take the necessary control measures.
I hope you’ve found this post helpful. If you haven’t don’t hesitate to let me know where it should be improved. Either way, leave a comment below.