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Spider mites are tiny bastards. You won’t see them until your plant looks like it’s been dusted with powdered sugar or wrapped in fine webbing. By then they’ve been feeding for weeks, sucking sap from leaves and turning your fiddle leaf fig into a sad stick.
The good news: they’re soft-bodied and easy to kill once you spot them. The bad news: they reproduce fast, so you need to act before they colonize every plant in your house. Here’s what works.
1. Blast Them Off With Water
The simplest method is often the best. Take your plant to the shower or sink and hit it with a strong spray of water, focusing on the undersides of leaves where spider mites gather. Use cold water if you can stand it (they hate cold).
Do this every 3-4 days for two weeks. You’re not poisoning them, just physically removing them and their eggs. Works best for plants with sturdy leaves that can handle the pressure. Skip this if you’ve got delicate ferns or African violets.
2. Insecticidal Soap
This is the step up from water. Insecticidal soap dissolves the mites’ waxy coating and dehydrates them. Mix according to package directions (usually 2-5 tablespoons per gallon of water) and spray until leaves are dripping.
Hit the undersides of every leaf. Spider mites hide where you’re not looking. Reapply every 5-7 days until you don’t see webbing or stippling on new growth. Don’t spray in direct sunlight or you’ll burn the leaves.
3. Neem Oil
Neem oil works as both a killer and a repellent. It disrupts the mites’ hormones so they can’t reproduce or feed normally. Mix 2 tablespoons of neem oil with a gallon of water and a few drops of dish soap (helps it stick to leaves).
Spray in the evening when temperatures are cooler. Neem can also burn leaves in bright sun. You’ll need to apply it weekly for at least three weeks to break the reproduction cycle. It smells weird but it works.
4. Horticultural Oil
Horticultural oil smothers mites on contact. It’s a step up in intensity from soap and works faster than neem. You can buy it ready-mixed or make your own with a few tablespoons of vegetable oil mixed with dish soap and water.
Spray thoroughly, coating all leaf surfaces. The oil needs to contact the mites to kill them. Don’t use this on stressed plants or in extreme heat. Wait at least two weeks before reapplying.
5. Isopropyl Alcohol Spray
For quick knockdown, mix one part 70% isopropyl alcohol with one part water in a spray bottle. This kills mites on contact and evaporates quickly, so there’s less risk of leaf damage than with oil-based treatments.
Test on a single leaf first. Some plants don’t tolerate alcohol well. If the leaf looks fine after 24 hours, spray the whole plant, focusing on webbed areas and undersides. Repeat every few days until the infestation clears.
6. Remove Heavily Infested Leaves
If a leaf is more web than green, just cut it off. You’re not saving it, and it’s a breeding ground that’ll reinfest the rest of the plant. Use clean scissors or pruning shears and wipe them with rubbing alcohol between cuts.
Bag the leaves and throw them in the trash. Don’t compost them. Spider mite eggs can survive and you’ll just spread the problem to your outdoor garden.
7. Quarantine the Plant
Spider mites spread fast between plants. As soon as you spot an infestation, move the affected plant away from others. Check neighboring plants for early signs (fine webbing, yellowing stipples on leaves).
Keep the infected plant isolated while you treat it. Wipe down the area where it was sitting with soapy water to kill any mites that dropped off. Don’t bring it back to the group until you’ve gone two weeks without seeing new damage.
8. Increase Humidity
Spider mites thrive in hot, dry conditions. They hate moisture. If your house is dry (especially in winter), boost humidity around your plants with a humidifier, pebble trays filled with water, or by grouping plants together.
This won’t kill an active infestation but it’ll make your plants less attractive to mites and slow their reproduction. Aim for 40-50% humidity. Your plants will look better anyway.
Spider mites are persistent but not invincible. Catch them early and you can knock them out with water and soap. Wait too long and you’ll need the heavier treatments. Check your plants every week, especially in winter when indoor air is dry and mites are most active. The ones you stop today won’t be the ones you’re battling next month.