Free Growli tool
Plant pest identifier
— tick the symptoms, see the pest.
Sticky leaves? White cotton in the leaf joints? A cloud of tiny flies when you water? Tick what you see — Growli ranks the 10 most common garden and houseplant pests and diseases by how well each one matches, with a treatment plan for the winner.
What do you see on the plant?
Tick every symptom that matches. The more boxes you check, the higher the confidence on the most likely culprit. 0/16 selected.
All 10 pests in the database
Already know what you're dealing with? Jump straight to the treatment guide.
Aphids
Aphidoidea
Tiny soft-bodied sap-suckers (often green, black, or peach) clustering on new growth and undersides of leaves. Multiply fast in warm weather and excrete sticky honeydew that breeds sooty mold.
Mealybugs
Pseudococcidae
Soft scale insects coated in a waxy white powder, hiding in leaf joints and along stems of houseplants. Suck sap, excrete honeydew, and spread fast across collections.
Spider mites
Tetranychidae
Microscopic arachnids that spin fine webbing between stems and feed on the undersides of leaves, leaving a stippled, dust-coated, fading appearance. Thrive in hot, dry indoor air.
Whitefly
Aleyrodidae
Tiny white moth-like insects that lift off in a cloud when you disturb the plant. Larvae feed on the leaf underside, weakening growth and coating leaves in honeydew.
Scale insects
Coccoidea
Sap-sucking insects hiding under hard or soft shells that look like brown, tan, or grey bumps glued to stems and leaf veins. Easily mistaken for plant tissue.
Fungus gnats
Sciaridae
Small dark flies that hover around the soil surface of overwatered plants. Adults are harmless to the plant, but their larvae feed on roots and fungi in chronically wet soil.
Slugs and snails
Outdoor nocturnal molluscs that chew ragged holes in leaves and tender stems, leaving silvery slime trails. Strike hardest in damp, mulched, shaded beds.
Powdery mildew
A fungal disease producing a dusty white-grey coating on the upper surfaces of leaves. Spreads in warm days + cool nights and humid stagnant air; eventually distorts and yellows foliage.
Root rot
Not a pest but a complex of soil fungi (Pythium, Phytophthora) that move on chronically waterlogged roots, turning them brown, soft, and unable to take up water. Wilting in wet soil is the giveaway.
Anthracnose
Colletotrichum spp.
A family of fungal diseases producing dark, sunken, water-soaked lesions on leaves, stems, and especially ripening fruit. Most damaging on beans, tomatoes, peppers, cucurbits, strawberries, and woody ornamentals during cool wet weather.
Need a wider net or a photo-based ID?
The Growli app identifies pests from a photo across 50+ species — including thrips, leaf miners, caterpillars, mites, and the bug-of-the-week your area is dealing with — and writes a treatment plan tuned to your exact plant and climate.
Open Growli — freePest identifier — frequently asked questions
How accurate is this pest identifier?
The identifier scores 10 of the most common garden and houseplant pests and diseases against the symptoms you tick. Tick at least two confirming symptoms (especially one from the "I can see the insect" group) to push confidence above 90%. The signs are drawn from extension service publications — but final ID still hinges on confirming the visual signs on the next screen, since several pests share overlapping symptoms.
What if my pest isn't in the database?
This tool covers aphids, mealybugs, spider mites, whitefly, scale, fungus gnats, slugs and snails, powdery mildew, root rot, and anthracnose — the pests and diseases behind ~80% of houseplant and home-garden problems. For thrips, leaf miners, caterpillars, or anything more unusual, snap a photo in the Growli app: the AI plant doctor handles a much wider range and tailors the advice to your specific plant.
I think it's spider mites but I can't see any insects — how do I confirm?
Hold a sheet of white paper or a tissue under a stippled leaf and gently tap. Spider mites show up as moving specks — they're only 0.4 mm long, so paper amplifies the contrast. If you see fine webbing in the leaf axils too, that's the deciding sign. They explode in hot dry indoor air, so misting the foliage every other day blunts the next generation while you treat.
My plant has sticky leaves but I can't see any pest — what is it?
Sticky leaves are almost always honeydew from a sap-sucking insect that's hiding. Check stem joints, leaf undersides, and new growth tips carefully — mealybugs nest in the joints, aphids cluster on new growth, scale sticks to stems, and whitefly hides on the underside. The tool ranks all four when you tick "sticky honeydew" so you can compare which secondary signs match.
Is "root rot" really a pest?
Strictly it's a disease complex caused by Pythium and Phytophthora fungi that thrive in waterlogged roots — not a pest in the insect sense. It's included here because the wilting-in-wet-soil symptom looks like a pest problem to a worried gardener, and the fix (let the root ball dry, repot into fresh free-draining mix, cut affected roots) overlaps with general care, so it gets surfaced early in the diagnostic flow.
Can I use this for outdoor garden pests too?
Yes — aphids, scale, powdery mildew, slugs and snails, and spider mites all attack outdoor vegetables, fruit, and ornamentals as well as houseplants. Whitefly and mealybugs are more common indoors but also hit greenhouses and protected outdoor crops. Fungus gnats and root rot are mostly houseplant or container-specific.
How is this different from the Growli app?
This is a one-shot symptom matcher — fast, free, and gives you the same shortlist a knowledgeable gardener would. The Growli app does the next step: you upload a photo, the AI plant doctor identifies the pest from the image (covering 50+ species, not just 9), and the treatment plan adjusts to your exact plant, climate, and stage of infestation.