app comparison
RHS Grow vs PictureThis 2026 — which suits UK gardens?
RHS Grow is £39.99/yr with a real free tier; PictureThis is £34.99/yr with a trial that converts. Official British advice against the biggest catalogue.
This is a comparison between an app backed by a 200-year-old British charity and the most-installed plant identifier in the world. They are not competing for quite the same job, and the honest answer for most UK gardeners involves both — one of which costs nothing.
This is a third-person comparison from the team behind Growli, an AI gardening assistant. We appear near the end as a third option; the substance is about these two.
Quick verdict — one sentence each
RHS Grow wins on British horticultural authority, on native and traditional garden plants, and on having a free tier that is actually worth using.
PictureThis wins on raw identification power across the world's ornamentals, and loses on billing behaviour.
Side-by-side
| RHS Grow | PictureThis Pro | |
|---|---|---|
| Annual price (UK) | £39.99 | £34.99 |
| Monthly | £5.99 | £3.99 / £7.99 short plans |
| Free tier | Real — A-Z profiles, Discover, garden lists | Trial only, converts automatically |
| Membership required? | No — separate from RHS membership | n/a |
| Catalogue | RHS A-Z, British-focused, expert-written | ~400,000 species claimed |
| Identification | Good, gated behind premium | Best in class |
| UK hardiness | Native RHS ratings | USDA zones |
| AI assistant | ChatBotanist (premium) | Botanist-on-call (premium) |
| Store rating (GB) | 4.7 (5,900) | 4.7 (166,000) |
The thing most pages get wrong about RHS Grow
Two corrections worth making, because both are widespread.
One: you do not need RHS membership. RHS Grow is separate from society membership and available to everyone. Paying for RHS membership does not include the app subscription, and subscribing to the app does not make you a member. We have seen the app described as a £58 member benefit; it is not.
Two: the free tier is real and quite good. The A-Z plant profiles are drawn from the RHS's own plant database and written by horticulturists rather than generated — for British garden plants they are the best free reference available in any app. The Discover articles and podcasts are free too.
What sits behind the £5.99/month or £39.99/year subscription: Plant ID, tailored care tips, the Journal, the Garden Planner and the ChatBotanist assistant.
One oddity worth flagging. The GB App Store listing for RHS Grow shows tiers at £29.99 and £34.99 alongside the £39.99, without stating what each covers. The RHS's own page publishes only £5.99 a month and £39.99 a year, so that is the figure to plan around — but do check what your paywall offers before agreeing to it.
RHS Grow — what it is genuinely best at
Authority on British plants. Two hundred years of horticultural knowledge, an expert-written A-Z, planting calendars tuned to UK regions, and — the part US-built apps simply cannot match — native RHS hardiness ratings rather than USDA zones translated across an ocean. If you are deciding whether something survives a British winter outdoors, this is the app whose answer means something.
ChatBotanist answers personalised questions in the paid tier, and it answers them in a British context.
Where it falls down: the identification engine is good but not best-in-class on global houseplants, and it is behind the paywall, so the free tier does not let you test the thing you would be paying for. The catalogue is British-weighted, which is the point but also the limit — an unusual tropical houseplant is likelier to defeat it than PictureThis. There is no daily briefing and no frost alerting.
PictureThis — what it is genuinely best at
Identification, across everything. A claimed 400,000-species catalogue, excellent reference photography, and a confident name in about two seconds. On houseplants, garden centre ornamentals and anything you photographed on holiday, it is the strongest option here by a clear margin. Paid tiers include botanist-on-call for follow-ups.
Where it falls down for a British gardener specifically: it is US-leaning. Care guidance arrives in USDA zones, seasonal timing is US-centric, and there is no RHS hardiness rating support — so advice about when to move something outdoors or whether it will overwinter needs translating. Care reminders are a static per-species card rather than a schedule that adapts.
And the billing. The 7-day trial converts to a paid annual subscription automatically, and unexpected charges after a trial people believed they had cancelled are the dominant theme in its UK reviews. Cancel through your phone's subscription settings — deleting the app cancels nothing.
Price, side by side
| Annual | Monthly | Free tier | |
|---|---|---|---|
| RHS Grow | £39.99 | £5.99 | Yes — real, no membership needed |
| PictureThis Pro | £34.99 | £3.99 / £7.99 short plans | No — 7-day trial only |
Read from the RHS's own page and the GB App Store listing on 29 July 2026.
PictureThis is £5 a year cheaper. RHS Grow gives you something usable for nothing. For most UK gardeners the second matters more than the first, because you can run RHS Grow's free tier indefinitely and decide later.
The honest recommendation, which is not one app
Install RHS Grow's free tier regardless. It costs nothing, the A-Z is the best free British plant reference in any app, and it will answer most garden-plant questions without a subscription.
Then decide what your recurring problem actually is:
- "I do not know what this plant is." If it is a British garden plant, RHS Grow's free A-Z often gets you there. If it is a houseplant or something exotic, PictureThis is worth the £34.99 — or use PlantNet, which is free with no in-app purchases at all and very good on natives and trees.
- "Will this survive my winter?" RHS Grow, without question. It is the only one of the two speaking in RHS hardiness ratings.
- "I keep losing plants and I do not know why." Neither app is built for this. PictureThis returns a static species page; RHS Grow returns an article. Diagnosing a sick plant means separating overwatering from light stress from nutrient burn, which look alike in a photo and need follow-up questions.
That last gap is where Growli sits — conversational diagnosis that narrows causes by asking, a daily briefing tying the British forecast to today's tasks, and frost alerts ahead of cold nights. Like RHS Grow, it carries native RHS hardiness ratings rather than converted USDA zones.
On price we are not undercutting either: Growli Plus is £34.99 a year, level with PictureThis and £5 under RHS Grow. Our free tier does not expire — garden plan, weather-timed care tasks, frost warnings, growing guides — with photo identification and diagnosis on the paid plan. All three UK prices are set out in how much plant apps cost in the UK.
Common mistakes
- Thinking RHS Grow needs membership. It does not, and believing it does is the most common reason British gardeners never try the free tier.
- Paying for PictureThis to get UK care advice. Its identification is excellent; its hardiness guidance is USDA-based and needs translating.
- Starting the PictureThis trial and forgetting. It converts automatically at £34.99.
- Assuming the £39.99 is the only RHS Grow price. The App Store listing shows £29.99 and £34.99 tiers too, without explaining them — check your paywall.
Related articles
- How much is the RHS Grow app? Cost and free tier — the price, the free tier, and the membership confusion
- 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 — including RHS Grow's free tier in detail
- Best plant care app UK 2026 — free and paid, 7 tested — the full UK field
- Best plant identifier app UK 2026 — tested and ranked — the identification side
- UK RHS hardiness ratings explained — what H1a to H7 actually mean
- Growli vs RHS Grow — where we differ from the official app
Prices verified against the RHS's own page and the GB App Store on 29 July 2026. Reviewed by the Growli editorial team.
Frequently asked questions
Is RHS Grow free, and do I need to be an RHS member?
There is a genuinely free version, and no, membership is not required. RHS Grow is separate from RHS society membership and available to everyone — paying for membership does not include the app subscription. The free tier covers the A-Z plant profiles from the RHS's own database, the Discover articles and podcasts, and your garden and wishlists. Plant ID, tailored care tips, the Journal, the Garden Planner and the ChatBotanist assistant sit behind £5.99 a month or £39.99 a year after a free trial. Checked against the RHS's own page, 29 July 2026.
Which is better for UK gardeners, RHS Grow or PictureThis?
RHS Grow, for anything growing in a British garden. It carries native RHS hardiness ratings rather than USDA zones, planting calendars tuned to UK regions, and an expert-written A-Z covering British natives and traditional garden varieties — and its free tier gives you most of that for nothing. PictureThis is better at raw identification, particularly for houseplants and exotic ornamentals, but its care and hardiness guidance is US-leaning and needs mental translation. Most UK gardeners are best served by RHS Grow's free tier plus a dedicated identifier.
How much does RHS Grow cost compared with PictureThis?
RHS Grow is £39.99 a year or £5.99 a month, on top of a free tier that keeps working. PictureThis Pro is £34.99 a year with no permanent free tier, only a 7-day trial that converts automatically. So PictureThis is £5 a year cheaper but gives you nothing for free, while RHS Grow costs slightly more and lets you use its best free feature — the A-Z plant profiles — indefinitely without paying. Both checked 29 July 2026.
Does RHS Grow identify plants as well as PictureThis?
No. PictureThis leads clearly on raw identification, with a claimed 400,000-species catalogue against RHS Grow's British-focused library, and it is markedly stronger on houseplants and exotic ornamentals. RHS Grow's identification is good and improving, and it is more likely to be right about a British native or a traditional garden variety — but it sits behind the paid tier, so you cannot test it on the free version. For free identification, PlantNet has no in-app purchases at all and is excellent on natives and trees.
Why do people get charged unexpectedly by PictureThis?
The 7-day free trial converts to a paid annual subscription automatically, and deleting the app does not cancel it — a distinction many people discover on a bank statement. It is the dominant theme in PictureThis's UK App Store reviews. Cancel through your iPhone or Android subscription settings if you are not sure you will keep it. Cancelling still gives you access until the trial period ends, so there is no reason to delay.
Can either app tell me if a plant will survive a British winter?
RHS Grow can, and this is its clearest advantage. It uses the RHS hardiness rating system (H1a to H7), which is built for British conditions and is what UK plant labels and nurseries actually use. PictureThis reports USDA zones, an American system that maps poorly onto a maritime climate — a plant rated for USDA zone 8 may or may not cope with a wet British winter, because the limiting factor here is often waterlogging rather than minimum temperature. For overwintering decisions, use an RHS rating.
Should I use RHS Grow and PictureThis together?
It is a sensible combination, and it can be a cheap one. RHS Grow's free tier costs nothing and gives you the best British plant reference available in an app; add PictureThis at £34.99 only if you regularly meet plants you cannot name. If identification is occasional, PlantNet is free with no in-app purchases at all and covers most of it, which makes RHS Grow free tier plus PlantNet a genuinely capable no-cost setup for a UK gardener.