The best bug spray for most indoor plants is a ready-to-use insecticidal soap. It kills aphids, spider mites, mealybugs, whiteflies, and young scale on contact, it has little smell, and it is made for use indoors. Horticultural oil and neem oil are the next two choices. No spray works on fungus gnats, which need a soil treatment instead.
The right pick depends on the pest. This guide matches each spray to the bugs it works on and lists what to look for on the label.
I earn a commission when you buy through links to Amazon. It costs you nothing extra.
Which spray for which pest
| Pest | Best first choice | Also helps |
|---|---|---|
| Aphids | Insecticidal soap | Strong rinse with water, neem oil |
| Spider mites | Insecticidal soap | Horticultural oil, rinsing every few days |
| Mealybugs | 70% isopropyl alcohol on a swab | Insecticidal soap, neem oil |
| Scale | Scraping by hand, alcohol swab | Horticultural oil for the young |
| Whiteflies | Insecticidal soap | Yellow sticky traps, neem oil |
| Thrips | Insecticidal soap, many rounds | Neem oil, sticky traps |
| Fungus gnats | Bti in the water (not a spray) | Yellow sticky traps, drier soil |
If you do not know which pest you have, start with how to get rid of bugs on indoor plants.
The four sprays worth buying
Insecticidal soap
What it is: potassium salts of fatty acids, mixed with water. It is not the same thing as dish soap.
How it works: it breaks down the outer layer of soft-bodied insects and mites, and they dry out. It only works while wet and only on bugs it touches. Once dry, it does nothing.
Good for: aphids, spider mites, mealybugs, whiteflies, thrips, and young scale.
Limits: it does not kill most eggs, so you spray again every 5 to 7 days. It can mark some plants, including ferns, some succulents, and plants with fuzzy leaves.
A ready-to-use insecticidal soap spray from Amazon is the one to buy first.
Horticultural oil
What it is: a refined mineral oil or plant oil made for spraying on leaves. Labels may say “all seasons” or “summer” oil.
How it works: it coats insects, mites, and their eggs, and they smother.
Good for: scale crawlers, spider mites and their eggs, mealybugs, and aphids.
Limits: it leaves a film, and it can burn leaves in direct sun. Do not use it on plants with a blue or powdery coating, since the coating will not come back.
Look for a horticultural oil spray labeled for indoor plants.
Neem oil
What it is: oil pressed from neem tree seeds.
How it works: it smothers like other oils. Cold-pressed products also contain azadirachtin, which puts insects off feeding and slows their growth.
Good for: aphids, mites, mealybugs, whiteflies, and early powdery mildew.
Limits: it has a strong smell that lasts a day or two. It works slowly. It burns leaves in sun. The full method is in how to use neem oil on indoor plants.
A ready-to-use neem oil spray saves you from mixing.
70% isopropyl alcohol
What it is: plain rubbing alcohol from the pharmacy shelf.
How it works: it dissolves the waxy coating on mealybugs and soft scale and kills them on contact.
Good for: spot treatment. Dip a cotton swab and touch each bug.
Limits: it is a swab tool, not an all-over spray. It can burn thin leaves. Test one leaf and wait a day.
What is not a spray, but works
- Bti. A soil bacterium that kills fungus gnat larvae. It is sold as Mosquito Bits or dunks. You soak it in your watering can. See how to use Mosquito Bits for fungus gnats.
- Yellow sticky traps. They catch flying adults: gnats, whiteflies, winged aphids, and thrips.
- Water. A firm rinse in the sink or shower removes aphids and mites before any spray goes on.
What to look for on the label
- “For indoor use” or “for houseplants.” Some garden sprays are for outdoor use only.
- The active ingredient. It will read “potassium salts of fatty acids” for soap, “mineral oil” or a plant oil for horticultural oil, or “clarified hydrophobic extract of neem oil” or “azadirachtin” for neem.
- Your pest by name. The label lists the pests the product is registered for.
- Your plant type, or a caution list. Good labels name plants that react badly.
- Ready-to-use or concentrate. Ready-to-use costs more per bottle and needs no mixing. A concentrate suits a large collection.
- A sprayer that works upside down. Most pests sit under the leaves. A trigger that sprays at any angle makes the job faster.
What to skip
- Homemade dish soap sprays. Dish soaps are detergents. They can strip the wax from leaves, and the strength of a home mix is a guess.
- Systemic insecticides. These are taken up into the whole plant. This site does not recommend them for houseplants in a home with kids, pets, or pollinators visiting plants that go outside in summer.
- Outdoor garden sprays. If the label does not say indoor use, do not use it indoors.
- Foggers and bug bombs. They do not reach under leaves, and they coat the room.
- Leaf shine with “pest control” claims. Shine products clog leaf pores and do not solve an infestation.
- Essential oil mixes with no label rates. Strong oils burn leaves, and many are unsafe around cats.
How to use any contact spray
Every spray on this page works the same way. It has to touch the bug.
- Move the plant away from the others.
- Rinse the plant and let it dry.
- Read the label, and follow it.
- Test one leaf. Wait 24 hours.
- Spray until wet. Cover leaf undersides, stems, and leaf joints.
- Keep the plant out of direct sun until it dries.
- Repeat every 5 to 7 days for at least 4 weeks.
Keep children and pets away until the spray dries, and store the bottle out of reach.
Plants that need extra care
Test first, and consider a swab or a rinse in place of a spray for these.
- Ferns and palms
- African violets and other fuzzy leaves
- Thin-leaved plants such as calathea
- Succulents with a powdery coating, such as echeveria
- Plants in bloom. Sprays can spot the flowers.
Why one spray is never enough
A spray is one part of the plan. The rest matters as much.
- Hand removal. Scale and mealybug adults come off with a swab or a fingernail. Sprays alone often fail on them. See how to get rid of scale on houseplants and how to get rid of mealybugs on houseplants.
- Repeat rounds. Eggs survive. Weekly rounds catch each new hatch.
- Growing conditions. Spider mites surge in furnace-dry winter air. Rinsing leaves and raising humidity slows them down.
- Quarantine. Keep new plants apart for 2 to 4 weeks.
What to buy first
- One or two plants with a soft-bodied pest: a ready-to-use insecticidal soap.
- Scale or mite eggs: add horticultural oil.
- Mealybugs: a bottle of 70% isopropyl alcohol and cotton swabs.
- Tiny flies around the soil: Bti and yellow sticky traps. Skip the leaf sprays.
- A large collection: a soap concentrate and a good pump sprayer.