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How to Get Rid of Spider Mites Organically
To get rid of spider mites organically, blast them off with a strong spray of water (especially the undersides of leaves), prune and destroy badly infested leaves, and treat with insecticidal soap or horticultural or neem oil, covering the leaf undersides and repeating every few days. Keep plants well-watered, since mites love hot, dry, dusty, stressed plants, and let natural predators build up. The one thing not to do is reach for a broad-spectrum bug spray: those kill the mites’ natural predators and usually make an outbreak worse.
Quick answer: Spray plants forcefully with water to knock mites off the undersides of leaves, remove heavily infested leaves, and apply insecticidal soap or neem/horticultural oil with thorough coverage, repeating because these only kill on contact. Keep plants watered and dust-free, and protect predatory mites and lady beetles by avoiding broad-spectrum insecticides, which actually trigger worse mite outbreaks. Do not spray soap or oil in the heat of the day (over about 90 degrees F) or on water-stressed plants.
| Method | How | Notes |
|---|---|---|
| Strong water spray | Blast mites off, especially leaf undersides | Also cuts dust; repeat every few days |
| Remove infested leaves | Prune and destroy badly infested parts | Slows the spread |
| Insecticidal soap or oil | Spray to cover leaf undersides; repeat | Contact-kill, no residual; not over 90 degrees F or on stressed plants |
| Natural predators | Encourage predatory mites, lady beetles, lacewings | Avoid broad-spectrum sprays that kill them |
| Keep plants watered | Reduce drought stress and dust | Healthy plants tolerate mites better |
What Are Spider Mites and How to Spot Them
Spider mites are not insects; they are tiny arachnids, more closely related to spiders, and they live in colonies mostly on the undersides of leaves, where they pierce plant cells to feed.[1] The most common one on garden plants and houseplants is the twospotted spider mite, about 0.4 mm long with eight legs and two dark spots on its back, so small you really need a hand lens to see it clearly.[2] A quick test: hold a sheet of white paper under a branch and tap it; if tiny specks fall and smear when you wipe them, you have mites. The damage itself is the giveaway, starting as fine stippling, a dusting of pale yellow or white speckles on the leaves, then bronzing and yellowing, and on heavy infestations you will see fine webbing over the leaves.[1]
Why Spider Mites Thrive
Spider mites love hot, dry, dusty conditions, which is why they often show up first on plants along dusty paths or roadsides, and water-stressed plants are especially vulnerable.[1] There is one more cause that surprises people: spraying broad-spectrum insecticides. Products like carbaryl, malathion, and the pyrethroids are not very effective on mites, they kill the predators that keep mites in check, and some even raise the nitrogen level in leaves in a way that boosts mite reproduction, so a bug spray aimed at other pests can actually trigger a spider-mite explosion.[1]
How to Get Rid of Spider Mites Organically
Start with water. A regular, forceful spray of plain water, aimed at the undersides of the leaves, knocks mites and their eggs off and is often enough on its own; it also washes away the dust they thrive in.[1] Prune off and destroy any badly infested leaves to slow the spread. If you need more, treat with insecticidal soap or a horticultural or neem oil: these work by contact, so you must cover the undersides of the leaves thoroughly, and because they leave no lasting residue you will need to repeat the treatment every several days.[3] Two cautions that matter a lot in Southern California: do not spray soap or oil when temperatures are above about 90 degrees F, in direct sun, or on a water-stressed plant, because that can burn the foliage, so treat in the cool of the morning or evening.[1]
Encourage Natural Predators
Your best long-term ally is the mites’ own predators. Predatory mites such as the western predatory mite, along with the spider-mite-destroyer lady beetle, sixspotted thrips, minute pirate bugs, and lacewing larvae, feed on spider mites and often control them for free.[1] The way to keep them working is simply to avoid broad-spectrum insecticides, which wipe out these beneficial bugs along with everything else; this is the single most important reason to stick with water, soap, and oil instead.[4] For more on the good bugs, see our guide to beneficial bugs for organic pest control.
How to Prevent Spider Mites
Prevention comes down to keeping plants unstressed and uninviting to mites: water deeply and regularly so plants are not drought-stressed, and hose or rinse dusty foliage now and then, especially on plants near paths and driveways.[1] For houseplants, inspect new plants before bringing them home and isolate any plant that shows mites; wipe or rinse the leaves, and if a plant is severely infested it is often best to discard it before the mites spread to the rest of your collection.[5] Spider mites can be stubborn and there is no one-and-done cure, but with steady watering, water sprays, and a hands-off approach to bug spray, most infestations come under control.
Dealing with a stubborn mite problem? Visit any Green Thumb Nursery location and our team will help you pick the right insecticidal soap or oil and the natural predators to get your plants healthy again. For more, see our guide to organic pest control.
Spider Mites FAQ
How do you get rid of spider mites?
Spray them off with a strong jet of water on the leaf undersides, remove badly infested leaves, and treat with insecticidal soap or neem oil, covering the undersides and repeating every few days. Keep plants watered and avoid broad-spectrum insecticides.[1]
What kills spider mites naturally?
Water sprays, insecticidal soap, and horticultural or neem oil all kill mites on contact, and natural predators like predatory mites and lady beetles kill them for you. Protect those predators by not using broad-spectrum sprays.[1]
What causes spider mites?
Hot, dry, dusty conditions and water-stressed plants favor spider mites. Broad-spectrum insecticides also cause outbreaks by killing the mites’ predators, so they often make the problem worse.[1]
Does soapy water kill spider mites?
Insecticidal soap kills mites on contact by breaking down their protective coating, but it has no lasting residue, so you must cover the leaf undersides well and repeat. Use a commercial insecticidal soap rather than a homemade dish-soap mix, which is more likely to damage the plant.[3]
Will spider mites go away on their own?
Not usually, especially in hot, dry weather. But with regular water sprays, steady watering, and healthy natural predators, most infestations can be brought under control; a severely infested houseplant may be best discarded.[5]
Sources
- [1] UC Statewide IPM Program, Pest Notes: Spider Mites: ipm.ucanr.edu
- [2] NC State Extension, Twospotted Spider Mite: content.ces.ncsu.edu
- [3] Clemson Cooperative Extension HGIC, Less Toxic Insecticides: hgic.clemson.edu
- [4] Washington State University HortSense, Spider Mites: hortsense.cahnrs.wsu.edu
- [5] NC State Extension, Spider Mites on Houseplants: henderson.ces.ncsu.edu
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I use a combination of natural Pyrethrin, 1.4%, and a good Horticultural Oil. I hit them first with the Pyrethrin to knock the population down and then I follow up with 3 spraying off the Horticultural Oil, 7 to 10 days apart, to keep the population down. I then spray as needed. Make sure that the Horticultural Oil being use does not have any heat restrictions on it. This combination use this way works great on almost all motes.
Great suggestion, I might give this combination a try the next time I spot a couple of these critters.
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