What's wrong with my plant? — best apps for diagnosis

What's wrong with my plant? — best apps for diagnosis

If you are searching for a "what's wrong with my plant" app, you have already done the hard part — you noticed something is off. The remaining job is figuring out which of half a dozen overlapping causes is responsible, and acting before the plant tips over. This guide is an honest ranking of the apps actually built for that job, including Growli, which is one of them.

We build Growli, so we have skin in the game. We will tell you exactly where each competitor wins and where ours does not.

Try the conversation: Open Growli, photograph the symptom, and answer one or two clarifying questions. A ranked diagnosis and a personalized fix in about 60 seconds.

What a plant diagnosis app should actually do

Before the ranking, a quick framing. Most plant problems collapse into a small set of overlapping causes that look very similar in a single photo:

• Overwatering and root rot — yellow lower leaves, mushy stem, soil staying wet for days. See overwatered plant and root rot.
• Underwatering — crispy edges, drooping, dry soil pulling away from the pot. See underwatered plant.
• Light stress — pale new growth or scorched patches depending on whether the plant is starved or burned.
• Pests — sticky residue, webbing, white cottony spots. See guides on aphids, spider mites, mealybugs, fungus gnats, and scale insects.
• Fungal disease — powdery white coating, fuzzy mold, black spotting. See powdery mildew.
• Nutrient deficiency or fertilizer burn — pale veins, brown leaf tips, salt crust on soil.

The honest truth: yellow leaves alone are compatible with five of those six causes. A single photo cannot reliably separate overwatering from underwatering from light stress. That is why the strongest plant diagnosis apps are the ones that ask follow-up questions before committing to an answer.

A diagnosis app worth installing should:

1. Accept a clear photo of the symptom and ideally the whole plant.
2. Ask about context — when you last watered, what the soil feels like, recent repot, light conditions, recent changes.
3. Rank causes, not commit to one. Probabilities and runners-up beat false certainty.
4. Give a specific fix — not "improve light" but "move two feet closer to the south window and skip the next watering."
5. Follow up. What does the plant look like in 7 days? Did the fix work?

Most apps do step 1. Few do all five.

The 3 best "what's wrong with my plant" apps in 2026

1. Growli — best conversational diagnosis

Growli is built around dialog. You photograph the leaf, and instead of returning a single confident species + generic FAQ, Growli asks the questions a knowledgeable friend would ask.

The typical flow on a yellowing leaf:

1. Photograph the leaf and a wider shot of the plant.
2. Growli: "When did you last water, and how does the soil feel today — soggy, damp, or dry?"
3. You answer.
4. Growli: "Have you repotted, fertilized, or moved the plant in the past month?"
5. You answer.
6. Growli ranks the most likely causes by your specific answers — for example, overwatering 62 percent, light stress 22 percent, fertilizer burn 10 percent, pest 6 percent.
7. You get a specific fix tied to your light, climate, and watering history.
8. Tomorrow morning's briefing includes a 7-day recovery checklist.

Pros: multi-turn dialog handles the overlap between overwatering, underwatering, and light stress that single-photo apps cannot separate. Daily morning briefing with weather and tasks. Frost alerts ahead of cold nights. Remembers your garden history across sessions. Native US and UK localization (USDA zones and RHS hardiness ratings). Offline mode for greenhouse and field use. Loved by 7,000+ growers.

Cons: dialog-first UX has a small learning curve if you expect a one-tap answer. Smaller species catalogue than PictureThis at the long tail of obscure ornamentals, though we extend monthly. Best on common US and UK home-garden species.

Use it if: you want to actually solve the problem, not just put a name on it.

2. PictureThis — best species ID, static diagnosis

PictureThis leads the market on raw species identification — the trained catalogue is the largest available — and bolts a diagnosis feature onto that engine. Photograph the leaf, get a species ID, then PictureThis returns a static page with the common issues for that species.

Pros: very fast identification, polished UI, large species catalogue, integrates the ID step well.

Cons: the diagnosis layer is essentially a per-species FAQ rather than a back-and-forth. There is no clarifying question about when you last watered or how the soil feels. If your problem is one of the three or four common ones in the FAQ, PictureThis often points you in the right direction. If it is not, the app has nothing more to say. Aggressive paywall with frequent complaints about unintended auto-renewals.

Use it if: identification is the harder half of your problem and you suspect the symptom is the most common one for that species.

3. greg.app — best community-plus-AI hybrid

Greg combines a watering scheduler, photo intake, and a friendly community feed. The diagnosis layer is part-app, part-other-humans. You post a photo with context and other plant owners chime in alongside the app's own suggestions.

Pros: the community is genuinely helpful and often catches things the app misses, especially on similar-looking cultivars and rare houseplants. Watering algorithm is solid for ongoing prevention. Clean calendar UX.

Cons: conversational depth is shallow — the app does not ask clarifying questions in dialog. Diagnosis quality depends on which community members happen to be online when you post. No weather-integrated briefing. No frost alerts. US-skewed defaults.

Use it if: you want a second human opinion alongside the app's suggestion and you are happy waiting a few hours for community replies.

Comparison table — what matters for diagnosis

No app wins every column. If you only care about identification speed, PictureThis wins. If you want crowd-sourced validation, greg.app wins. If you want a diagnosis dialog that actually separates overlapping causes, Growli wins.

Why Growli's conversation flow beats one-shot photo

Most plant diagnosis apps work in one step: photo in, answer out. That works fine for unambiguous symptoms — clear powdery mildew, an obvious aphid colony, a webbed-up spider mite infestation. It fails on the most common symptoms, which all look the same in a photo.

Yellow lower leaves can mean:

• Overwatering (the most common cause)
• Underwatering
• Natural aging of older foliage
• Nutrient deficiency
• Low light

Drooping can mean:

• Underwatering
• Overwatering and early root rot (counter-intuitive but common)
• Sudden temperature shift
• Transplant shock
• Pests

A single photo cannot reliably separate these. The cues a knowledgeable gardener uses — when did you last water, how does the soil actually feel, has anything changed recently — are not visible in the leaf. They have to be asked.

That is the entire wedge for Growli. We ask the questions, you answer in two or three taps, and the app ranks causes by what you actually told it rather than by what the leaf alone could betray.

A worked example — your peace lily is drooping.

A single-photo app: "Your peace lily looks drooping. Common causes include underwatering, overwatering, low light, and pests. Try checking the soil."

Growli: "How does the soil feel — soggy, damp, or dry?" → "Damp." → "When did you last water?" → "Three days ago." → "Is the plant near a heating vent or drafty window?" → "Heating vent." → "Most likely cause is heating-vent dehydration combined with dry indoor air, not a watering issue. Move it three feet from the vent and mist daily for a week. Skip the next watering until the top inch is dry."

The second answer is actionable. The first is a checklist.

For comparable in-depth guidance see what's wrong with my plant — the 60-second triage, the deep dive on overwatered vs underwatered, and the broader plant care app overview.

Diagnose this with Growli: Open Growli, describe the symptom in plain English, and you will get a personalized fix — calibrated to your plant, your climate, and the last time you watered.

When to skip the app entirely

A diagnosis app is the right tool for ambiguous symptoms. It is the wrong tool for problems that need immediate action. Skip the app and act if you see:

• A visible pest infestation. Spider mite webbing, aphid colonies, mealybug white fluff, or scale bumps on stems mean you have already diagnosed the problem. Isolate the plant and treat now. See aphids, spider mites, mealybugs, and scale insects.
• Advanced root rot. If the plant is wilting hard, the stem is mushy at the base, and the soil smells sour, the problem is already diagnosed. Unpot the plant, trim black mushy roots, repot in fresh dry mix. See root rot and how to revive a plant.
• Frost damage on outdoor plants. Blackened soft growth after a cold night is unmistakable. Prune damaged growth back to healthy tissue and protect for the next freeze.
• Pet emergency. If a cat or dog has eaten a plant, identification and toxicity confirmation matter more than the plant's health. Skip the app, photograph the plant, and contact your vet or the ASPCA Animal Poison Control line in the US, or Animal PoisonLine in the UK.

For everything in between — yellow leaves, drooping, brown tips, slow growth, pale new leaves — a diagnosis app saves you from guessing.

Common mistakes when using a plant diagnosis app

1. One photo, low light. Take the plant near a window before snapping. Bad light produces bad diagnoses.
2. Skipping the context questions. If the app asks when you last watered, answer honestly — even "I do not remember" is useful information.
3. Trusting a single confident answer. Yellow leaves alone match five different causes. A diagnosis ranked at 99 percent with no runners-up is suspicious. Look for probability distributions.
4. Treating before you diagnose. Adding fertilizer to a yellowing plant that is actually overwatered makes things worse. Diagnose first, then act.
5. Acting once and stopping. Plants recover over days, not hours. Set a 7-day check-in and re-photograph to see whether the fix is working.
6. Forgetting outdoor context. Frost, heatwave, drought — climate matters as much as care. An app with weather integration catches this; a static FAQ does not.

Action plan — diagnose your plant this week

• Right now (5 min): Photograph the symptom and the whole plant in window light. Open Growli or your chosen app, and answer the clarifying questions honestly.
• Act on the ranked top cause. Fix one variable at a time — do not water, fertilize, and repot in the same week. One change, observe, then iterate.
• Re-check in 7 days. Photograph again. If the symptom is stable or improving, the diagnosis was right. If it is worse, re-run the dialog with the new photo and the new answer to "what did you try?"
• If the plant is past saving, propagate. Many sick houseplants have healthy cuttings worth saving. See how to propagate pothos for the easiest case.

Related articles

• What's wrong with my plant? 60-second triage guide — the underlying diagnostic framework
• Best plant identifier app 2026 — tested and ranked — sister ranking covering identification
• PictureThis alternatives — 7 plant ID apps compared — broader app comparison
• Plant care app — what to look for in 2026 — care-app overview after diagnosis
• Why is my plant dying? — deeper diagnostic walk-through
• How to revive a plant — once you have a diagnosis, the recovery playbook

Reviewed and updated by the Growli editorial team. For questions about anything here, open Growli and ask — or email hello@getgrowli.app.