Best Plant Identifier App UK 2026 — Free Picks Tested

There are roughly two dozen plant identifier apps in the UK App Store and Google Play UK, but only six matter in 2026 for British gardeners: PictureThis, PlantNet, RHS Grow, Seek by iNaturalist, Greg and Growli. This is an honest ranking — Growli built and ships one of the apps in this list, so we have skin in the game, but we are going to tell you exactly where each competitor wins in UK conditions.

If you only remember one thing: photo-only identification is now a commodity. The differentiator in 2026 is what happens after the species name comes back. For British gardeners that means RHS hardiness ratings (not USDA zones), UK-specific care timing (when does Tomorite season actually start in your region?), and frost alerts tuned to the British forecast. If you came here from the PictureThis question specifically, our roundup of PictureThis alternatives for UK gardeners and the wider plant care app comparison go deeper on the after-ID experience.

Try the conversation: start Growli's 7-day Plus trial, photograph a plant, and ask follow-up questions in plain English — identification plus a personalised UK care plan in about 60 seconds. Rated 4.8★ on the App Store.

The 6 best plant identifier apps for UK gardeners

1. PictureThis — best for raw species catalogue

PictureThis is the market leader by a wide margin in the UK App Store. An enormous trained species database, polished onboarding flow, and roughly 109,000 US-equivalent organic visits per month worldwide. If you point your phone at almost any plant on Earth, PictureThis will return a confident species name in two seconds.

Pros: highest species coverage, very fast, strong on ornamentals and houseplants, clean UI, works on UK garden plants well thanks to broad European training data.

Cons: aggressive paywall (most useful features require a subscription), care advice is static per-species FAQ rather than personalised, no real back-and-forth dialog for symptom diagnosis, frequent complaints in UK App Store reviews about auto-renewal billing, US-leaning defaults (USDA zones rather than RHS hardiness ratings).

UK pricing: £34.99 a year for PictureThis Pro after the 7-day free trial, with £3.99 and £7.99 short plans, a £39.99 tier, and a £49.99 Family Plan also listed. Read from the GB App Store on 29 July 2026. Most comparison pages, including an earlier version of this one, quote around £25 — that figure is out of date.

Use it if: you mostly need to know "what is this plant?" and do not care about ongoing UK-specific care guidance.

2. PlantNet — best free and open-source option

PlantNet is run as a citizen-science project by a French research consortium (Cirad, INRA, INRIA, IRD). It is free, ad-free, and uses crowd-contributed identifications to train its model. For UK wild plants, weeds, hedgerow species and field botany it is the most credible option on the market.

Pros: completely free forever, no paywall, strong on European wild and native species (which suits the UK well), transparent about confidence scores, no nag screens, popular with British plant enthusiasts.

Cons: weaker on cultivated houseplants and ornamentals than PictureThis, minimal care advice layer, no symptom diagnosis, UI is functional rather than friendly.

Use it if: you are a UK hiker, naturalist, allotment owner, or field botanist who wants accurate identification on wild and native British species and does not need care recommendations.

3. RHS Grow — free tier, or £5.99/month (£39.99/year)

RHS Grow is the official app of the Royal Horticultural Society, launched in 2024 and now well-established in the UK market. It combines plant identification with the RHS's 200-year archive of British horticultural knowledge — including the RHS hardiness ratings, planting calendars tuned to UK regions, and a ChatBotanist feature for member queries.

Pros: official RHS curation, strong on British native plants, hedgerow species, garden ornamentals and traditional UK varieties, RHS-aligned care advice, ChatBotanist for personalised UK questions, supports member benefits.

Cons: identification engine is good but not best-in-class on cultivated houseplants compared to PictureThis, full features need a paid subscription after the free trial, smaller global species catalogue than PictureThis.

UK pricing: free version with core features; full access is £5.99/month or £39.99/year after a free trial — a subscription separate from RHS membership (you do not need to be an RHS member). The full breakdown, including the App Store tiers the RHS's own page does not mention and why members still pay, is in how much is the RHS Grow app?

Use it if: you primarily garden outdoors in the UK, or value RHS-aligned advice on UK natives and traditional British garden plants.

4. Seek by iNaturalist — best for biodiversity logging

Seek is a side-project of iNaturalist, a Cal Academy and National Geographic biodiversity database. It is gamified — earn badges for spotting species — and feeds observations back into a real scientific dataset that includes substantial UK records.

Pros: free, no account required for basic use, conservatively confident (it will tell you "genus only" rather than guess a species), contributions support real UK biodiversity research via iRecord and similar projects, family-friendly for kids.

Cons: not designed for personal plant care, no watering or fertilising advice, intentionally vague on cultivated UK garden varieties.

Use it if: you are cataloguing what grows on your allotment or garden boundary, hiking British uplands with kids, or supporting a UK citizen-science project. Skip it for indoor plant care.

5. Greg — best photo-light plant tracker

Greg (greg.app) is the closest peer to Growli — an app-led plant care advisor with a clean UI, watering reminders, and a small community feed. Greg's flagship is its watering algorithm, which factors in your pot size, light, and species.

Pros: elegant watering scheduler, good calendar UX, friendly community of houseplant owners, decent symptom photo intake, available in the UK App Store and Google Play UK.

Cons: conversational depth is shallow — it is mostly a calendar with notifications, no daily weather-integrated briefing, identification engine is not best-in-class, US-skewed defaults (USDA zones, US retailer references, no native RHS hardiness rating support).

UK pricing: Greg's GB listing shows ten SUPER Greg products from £3.49 to £49.99 with no durations published, so no honest annual figure exists — any page quoting one is guessing. Checked 29 July 2026.

Use it if: you have a fixed indoor collection of 5-30 plants and want a smart scheduler more than a diagnostic conversation, and you do not mind translating US-style guidance into UK conditions.

6. Growli — best conversational AI plant assistant with native UK support

Growli is built around a different premise: identification is the easy part, and the value is in the conversation that comes after. Snap a photo, then talk to Growli in plain English about what you are seeing, what you have already tried, and what the British weather is doing this week.

Pros: conversational symptom diagnosis (Growli asks clarifying questions and adapts), daily morning briefing with UK weather and tasks, frost alerts ahead of cold nights tuned to the British forecast, remembers your garden history, native UK localisation with RHS hardiness ratings (not just USDA zones), offline mode for greenhouse or field use, rated 4.9 in the UK App Store and 4.6 in the US across the UK and US.

Cons: smaller species catalogue than PictureThis at the long tail of obscure ornamentals (we are catching up monthly), best on common UK and US home-garden species, dialog-first UX has a slight learning curve for users expecting a one-tap answer.

UK pricing: the free tier does not expire and covers the garden plan, weather-timed care tasks, frost warnings and growing guides. Growli Plus is £34.99 a year (£6.99 a month) and adds photo identification, photo diagnosis with a treatment plan, and unlimited chat, with a 7-day free trial on the yearly plan. That is exactly level with PictureThis Pro in the UK — we do not undercut it, and this page said £24 until 29 July 2026, which was wrong. See the pricing page for the full split.

Use it if: you want a full UK gardening assistant rather than a one-shot photo lookup — especially if you grow a mix of indoor and outdoor plants and need season-aware advice calibrated to British conditions.

Decided? Start the 7-day Plus trial — photo ID and diagnosis included, £34.99/yr only if you stay, and the garden plan, care tasks and frost alerts stay free either way. Rated 4.8★ on the App Store.

Comparison table — the seven criteria that matter for UK gardeners

No app wins every column. The table is intended to make the trade-offs explicit so you can pick the one that matches your UK use case.

How to choose based on your actual UK need

A short decision framework for British gardeners:

• "I just want to know what this plant is, fast." → PictureThis (paid) or PlantNet (free).
• "I want to identify British wild flowers, trees, and weeds on a country walk." → PlantNet, RHS Grow, or Seek.
• "I am an RHS member and want official RHS advice." → RHS Grow.
• "I am logging UK biodiversity for a research project or kids' homework." → Seek by iNaturalist (feeds iRecord).
• "I have 10 houseplants in a British flat and I forget to water them." → Greg or Growli.
• "My plant is sick and I need to figure out what is wrong." → Growli (the symptom diagnosis flow is the wedge here).
• "I want morning briefings, frost alerts, and seasonal task lists tuned to UK weather." → Growli.
• "I am a UK gardener and need RHS hardiness ratings, not just USDA zones." → Growli or RHS Grow.

If you are choosing one paid app to keep on your phone, the honest answer for UK gardeners is: PictureThis if you mostly identify, RHS Grow if you mostly garden outdoors in the UK with RHS-aligned advice, Growli if you mostly care for plants you already own and want UK-native localisation. Many British growers run both an identifier and a care assistant.

Why Growli is different from photo-only apps

Photo-only apps answer one question: what is this plant? That is a lookup problem, and at this point in 2026, several apps solve it well.

Growli is built around a harder question: what does my specific plant need this week, in my UK region, given what I have already tried? That is not a lookup — that is a dialog.

The Growli flow on a sick UK plant:

1. Photograph the symptom.
2. Growli asks: "When did you last water? How does the compost feel today?"
3. You answer.
4. Growli asks: "Have you repotted, fertilised with Tomorite, or moved the plant in the past month? When did your central heating switch on?"
5. You answer.
6. Growli ranks the most likely causes by your specific answers — overwatering, low UK winter light, central-heating dry air, pest, or environmental stress.
7. You can ask follow-ups: "What if I have already tried that?" or "Is it safe for my cat?"
8. The next morning, your briefing includes a 7-day recovery checklist plus any UK frost warnings.

That conversation is the wedge. For comparable in-depth guidance see What's wrong with my plant — UK 60-second triage and the deep-dive on yellow plant leaves UK.

Diagnose this with Growli: start the free 7-day Plus trial, describe the symptom in plain English, and you will get a personalised fix — calibrated to your plant, your UK climate, and the last time you watered.

Free vs paid plant identifier apps in the UK

Most plant ID apps follow one of three monetisation patterns in 2026:

Free with a real free tier: PlantNet, Seek, and the basic tier of RHS Grow. No paywall, no nag screens for these three. PlantNet is funded by research consortia; Seek is funded by Cal Academy; RHS Grow basics are funded by the RHS. These are the genuinely free options for UK gardeners.

Free trial that converts to paid subscription: PictureThis, Greg and Growli all use a freemium model. PictureThis is the most aggressive — many UK App Store reviews report unintentional auto-renewals. Greg and Growli use lighter free tiers with a paid upgrade for advanced features.

Pay-once apps: rare in 2026. The compute cost of running a strong identification model favours subscriptions.

Honest UK pricing rule of thumb for 2026:

• PictureThis: £34.99 GBP per year.
• SUPER Greg: UK price not verified.
• Growli Plus: £34.99 GBP per year — conversational diagnosis, frost alerts, offline mode.
• RHS Grow: free version, or £5.99/month / £39.99/year for full features (separate from RHS membership).
• PlantNet and Seek: free forever.

If budget is your top constraint, PlantNet is the most credible free option for UK gardeners and there is no shame in stopping there. And note that RHS membership does not include RHS Grow — the RHS states the app subscription is separate and available to everyone, so members who want full access pay for it like anyone else.

Common mistakes when choosing a plant ID app in the UK

1. Picking on App Store star rating alone. UK App Store reviews are gamed; identification accuracy in independent tests is what matters. PictureThis and PlantNet consistently lead.
2. Assuming "best identification" means "best app." Identification is one feature. If your plants are already identified, you need an advisor, not another scanner.
3. Ignoring UK localisation. US-leaning apps recommend USDA zones; UK gardeners need RHS hardiness ratings and different planting calendars (Tomorite season starts in late spring, not February; British central heating is the dominant indoor stressor). Check which your app supports.
4. Trusting a single confident answer. A good app gives you a confidence score and shows close alternatives. Be sceptical of apps that always answer with one species at 99%.
5. Forgetting to cancel a free trial. UK auto-renewal complaints against PictureThis are extremely common — cancel inside the App Store or Google Play subscription settings, not by deleting the app.

Action plan — picking one this week

• Today (5 min): Decide which of the three jobs matters most — quick ID, ongoing UK care, or symptom diagnosis. The decision framework above maps each job to a winner.
• This week: Install the recommended app and identify five plants you already own to test accuracy. Most apps offer a 7-day free trial — use it before committing.
• This month: Track which feature you actually use day to day. If you have stopped using the identifier and started using the care log, you picked the right app. If not, switch.

Related articles

• How much is the RHS Grow app? Cost and free tier — the price, the free tier, and the membership confusion
• Growli vs Greg — honest 2026 comparison — the closest care-first competitor, compared
• Growli vs PictureThis — honest 2026 comparison — where we differ from the identification leader
• How much do plant apps cost in the UK? 8 verified — every GB price read from its own App Store listing
• Best free plant apps UK 2026 — 4 that stay free — PlantNet, Seek, RHS Grow and Growli's free tiers
• RHS Grow vs PictureThis — which suits UK gardens? — head-to-head on identification and British hardiness
• PictureThis alternatives UK — 7 plant ID apps compared — when the ID-app paywall stops being worth it
• Best plant care app UK — free and paid, 7 tested — care-side comparison
• What's wrong with my plant? UK 60-second triage — Growli's symptom diagnosis wedge
• Why are my plant leaves turning yellow? UK guide — the most common single symptom
• Indoor plant care UK basics — the foundations every British grower needs
• Snake plant care UK — beginner-friendly British houseplant guide
• UK RHS hardiness ratings explained — the canonical UK reference
• The State of Houseplant Toxicity 2026 — why identifying a plant matters before you bring it home: 63.8% of 5,561 species we analysed are harmful to pets
• PictureThis vs PlantNet — which identifies better? — the head-to-head between the paid leader and the free one

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