Most plant apps are built in the US, and it shows. They talk in USDA hardiness zones, assume a continental climate, and schedule your planting for a calendar that does not match a mild, damp British summer. For a UK gardener, that mismatch matters. This guide is an honest 2026 round-up — Growli makes one of the apps below, so we have skin in the game, but we will tell you exactly where each competitor wins.
What UK gardeners actually need from a plant app
Before the rankings, three things separate a genuinely UK-ready app from a repackaged US one.
RHS hardiness ratings, not USDA zones. The Royal Horticultural Society rates each plant on a single scale from H1a to H7 — nine bands based on the absolute minimum winter temperature a plant will tolerate. That is a different system from the USDA zones most American apps use, which are built on long-term average extreme minimums. Most of England and Wales sits around H4–H5; Cornwall and the Channel Islands behave more like H3, and the Scottish Highlands like H6–H7. An app that only speaks in USDA zones cannot tell you whether a plant will overwinter in your garden. We break the system down fully in our UK hardiness zones guide and map it region by region on the UK zones page.
Frost timing that matches your location. The UK's last-frost and first-frost dates swing widely between the mild south-west and the colder north and east. Generic "spring planting" reminders are close to useless. What helps is a frost alert ahead of a cold night, calibrated to where you actually garden.
Advice that recognises British conditions. Damp, cool summers, short winter days and heavy clay soils change how you water, feed and overwinter plants. An app that assumes bright, dry heat will over-recommend watering and under-warn about root rot.
The best plant apps for the UK, compared
| App | Best for | UK localisation | Free? | Platforms |
|---|---|---|---|---|
| PictureThis | Fast, broad identification | US-leaning (USDA zones) | Free trial, then paid | iOS, Android |
| PlantNet | Free, science-backed ID | Regional flora filter (can narrow to UK) | Fully free | iOS, Android |
| Seek (iNaturalist) | Wild plants and family use | Global, no zone logic | Fully free | iOS, Android |
| Planta | Care scheduling and reminders | Uses local weather data | Subscription | iOS, Android |
| Greg | Community-calibrated watering | US-skewed defaults | Generous free tier, paid schedules | iOS, Android |
| Growli | UK-aware care and diagnosis | RHS H1a–H7 + frost/postcode advice | Free | iOS, Android |
No app wins every column. Here is where each one earns its place.
PictureThis — best for fast, broad identification
PictureThis is the market leader on raw identification. It covers a very large species catalogue and returns a confident name in a couple of seconds, with strong accuracy on common houseplants and garden flowers.
Pros: huge catalogue, quick and polished, reliable on ornamentals.
Cons: most useful features sit behind a subscription (around £25–£30 per year after the trial), care advice is a static per-species FAQ rather than personalised, and its climate guidance leans on US zones rather than RHS ratings.
Use it if: you mostly want to know "what is this plant?" and are not fussed about UK-specific care.
PlantNet — best free option for UK plants
PlantNet is a citizen-science project backed by French research bodies (CIRAD, INRAE and Tela Botanica). It is completely free, with no paywall and no ads. Its stand-out feature for British gardeners is the regional flora filter: you can narrow identification to a European or UK flora, which helps rule out North American look-alikes and improves accuracy on native and naturalised species.
Pros: genuinely free, strong on wild and native plants, regional flora filter is a real UK advantage, transparent confidence scores.
Cons: weaker on cultivated houseplants and ornamentals, minimal care layer, no symptom diagnosis, a plainer interface.
Use it if: you walk the hedgerows, meadows and woodlands and want accurate ID on British wild plants for free.
Seek by iNaturalist — best for families and wild spotting
Seek is a free, private companion to iNaturalist. It needs no account, works well for children, and feeds observations into a real biodiversity database.
Pros: free, private, no sign-up, gamified for kids, contributes to citizen science.
Cons: no plant-care features, no disease diagnosis, and it is deliberately cautious — often stopping at genus rather than naming a cultivar.
Use it if: you want to catalogue what grows around you or get children interested in nature. It is not built for indoor plant care.
Planta — best for structured care scheduling
Planta is a polished care app that uses local climate and weather data alongside a multi-parameter algorithm to schedule watering, and includes a photo identifier and a "Dr. Planta" diagnosis flow.
Pros: attractive interface, weather-aware watering, tidy reminder system, built-in diagnosis.
Cons: it moved to a subscription-only model in 2026 (around £50–£60 per year at the time of writing), so there is little free functionality, and its hardiness guidance is not RHS-native.
Use it if: you want a slick scheduler and don't mind paying a subscription.
Greg — best community-calibrated watering
Greg is the closest peer to Growli — an app-led care advisor with a clean interface and a watering algorithm calibrated against a large community of plant owners in similar climates.
Pros: generous free tier (unlimited plant tracking and community advice), watering schedule that adapts to your feedback, friendly community.
Cons: care schedules and notifications require the paid tier, the identification engine is not best-in-class, and defaults are US-skewed rather than RHS-aligned.
Use it if: you have a fixed indoor collection and want a smart, community-tuned watering scheduler.
Growli — best for UK-aware care and diagnosis
Growli is built around a different premise: identification is the easy part, and the value is in the care conversation afterwards. Snap a photo, then talk to Growli in plain English about symptoms, what you have already tried and what the weather is doing this week.
Its UK edge is concrete. Growli uses RHS hardiness ratings (H1a–H7), not USDA zones, so overwintering advice actually reflects British conditions. It sends frost alerts ahead of cold nights, tuned to your postcode, and layers ASPCA pet-safety data across a library of roughly 11,700 species. It is free on iOS and Android, rated 4.6 on the App Store, and used by 7,000+ growers.
Pros: conversational symptom diagnosis, RHS-aligned hardiness, postcode frost alerts, pet-safety data, free core, daily care plan.
Cons: a smaller identification catalogue than PictureThis at the long tail of obscure ornamentals, and a dialogue-first interface that takes a moment to learn if you expect a one-tap answer.
Use it if: you garden in the UK and want season-aware, climate-correct care rather than a one-shot photo lookup.
How to choose the right plant app for you
- "I just want to name this plant, fast." → PictureThis (paid) or PlantNet (free).
- "I want to identify British wild flowers and trees." → PlantNet or Seek.
- "I need care advice that matches the UK climate and frost dates." → Growli.
- "I want a tidy watering scheduler." → Greg or Planta.
- "Is this plant safe for my cat or dog?" → Growli, which carries ASPCA pet-safety data. Browse our pet-safe plant hub to check before you buy.
If you are keeping one app on your phone, the honest answer is: PictureThis if you mostly identify, Growli if you mostly care for plants in a British garden. Many gardeners run both. For a deeper look at the identifiers specifically, see our best plant identifier app round-up, and for the wider category of care tools browse the plant-care hub.
Related articles
- UK hardiness zones — RHS H1a to H7 ratings explained — how to read the RHS scale for your garden
- UK zones map and postcode guidance — where your region sits on the hardiness scale
- Best plant identifier app 2026 — tested and ranked — the identification apps compared in depth
- Pet-safe plant hub — check toxicity before you buy, backed by ASPCA data
Reviewed and updated by the Growli editorial team. For questions about anything here, open Growli and ask — or email hello@getgrowli.app.
Frequently asked questions
What's the best free plant identification app in the UK?
PlantNet is the strongest fully-free identifier for UK gardeners. It is backed by a research consortium, has no paywall or ads, and includes a regional flora filter so you can narrow identification to UK or European plants and rule out North American look-alikes. Seek by iNaturalist is also free and better suited to families and wild spotting.
Which plant app works for UK hardiness ratings?
Growli uses the RHS hardiness scale (H1a–H7) rather than USDA zones, so its overwintering advice reflects British winter temperatures. Most US-built apps default to USDA zones, which do not map cleanly onto the UK. If hardiness and frost timing matter to you, an RHS-aligned app avoids advice built for the wrong climate.
Is PictureThis good for the UK?
PictureThis identifies UK plants accurately and quickly — its identification engine is climate-agnostic, so a British daisy is recognised as easily as an American one. The weaker point is care guidance: it leans on US hardiness zones and static per-species advice, so it is less useful for UK-specific overwintering, frost timing and watering decisions.
What's the difference between RHS ratings and USDA zones?
USDA zones divide the map into geographic bands based on long-term average extreme minimum temperatures. The RHS instead gives each plant a single hardiness rating from H1a to H7, based on the absolute minimum temperature it can survive. Most of England and Wales sits around H4–H5. Our UK hardiness zones guide explains how to read the ratings.
Which plant app is best for care reminders in the UK?
Greg, Planta and Growli all handle care reminders. Greg has a generous free tier with community-calibrated watering; Planta is a polished subscription scheduler using local weather data; Growli adds RHS-aligned hardiness, postcode frost alerts and conversational diagnosis on a free core. For UK-specific timing, an app that uses your local frost dates is the safer choice.
Are any good plant apps completely free?
Yes. PlantNet and Seek by iNaturalist are fully free with no paywall, funded by research and conservation organisations. Greg offers a generous free tier for plant tracking, though schedules need a subscription. Growli is free to download on iOS and Android with a free core covering identification and care. Planta and PictureThis are largely subscription-based.