Planta, Plant Parent, PictureThis and PlantNet compared — watering schedules based on real conditions, photo diagnosis of sick leaves and free plant identification.
Most houseplants do not die from neglect — they die from kindness. A fixed alarm that repeats "water every seven days" ignores species, pot size, light and season, and it reliably drowns the plants that need less in winter. The apps that genuinely help calculate instead, and pair watering with photo diagnosis for the yellow leaf or the pest you cannot name. The two apps reviewed below take different routes: one computes schedules from the actual conditions, the other diagnoses problems from a leaf photo. The FAQ covers the finger test, overwatering signs and what is genuinely free.
Planta calculates watering from species, pot size, light and season instead of a fixed weekly alarm, and includes a camera light meter.
Rather than firing off the same reminder every seven days, it works out when each plant needs water from its species, the pot size, the light it receives and the time of year — the contextual calculation that prevents overwatering, the leading cause of houseplant death, rather than causing it. The useful features require a subscription, its identification is weaker than PictureThis, and the database has noticeable gaps on rarer species.
Pros
Watering based on species, pot, light and season
Targets overwatering, the main killer of houseplants
Plant Parent diagnoses a yellowing or spotted leaf from a photo — overwatering, poor light or pest — then explains the treatment.
It pairs photo identification with problem diagnosis: show it a single yellow or spotted leaf and it indicates whether the cause is too much water, insufficient light or a pest, with the matching treatment and a strong houseplant focus. Personalised watering reminders are included, but free queries are capped low, the diagnoses are indicative rather than certain, and the app pushes its subscription fairly hard once the trial queries run out.
Pros
Diagnoses problems from a photo of one leaf
Strong focus on indoor plants
Personalised watering reminders
Cons
Low limit on free queries
Diagnoses are indicative only
Pushes the subscription fairly hard
Download price only. In-app purchases and subscriptions may cost extra.
Questions & answers
How often should you water a houseplant?
There is no single interval, and that is exactly the problem with fixed reminders. It depends on species, pot size, soil, light, temperature and season: the same plant may need water every four days in August and every twenty in January. The practical rule is to push a finger two centimetres into the soil and water only if it feels dry there.
How do I know if I am overwatering?
The usual signs are yellow, soft leaves starting from the bottom, permanently damp soil, small flies around the pot and a musty smell. It is often mistaken for underwatering because the plant also wilts, which leads to yet more water and makes things worse. Plant Parent and PictureThis are fairly good at telling the two causes apart from a clear leaf photo.
What is the best free plant care app?
None of these is completely free: they all limit queries or reminders on the free plan. PictureThis allows a few free identifications per day, and Planta lets you manage a handful of plants without paying. If you only want to identify plants rather than manage their care, PlantNet is entirely free and very accurate, so a free-plus-paid combination is the sensible setup.
Do they work for outdoor plants and vegetable gardens?
They work, but they are clearly built around indoor plants. For a vegetable patch or a garden, the factors that matter — local climate, soil type, sowing calendars — fall outside what these apps calculate. They handle identification and common pests well, but they do not replace a growing guide written for your area and its conditions.
More related apps
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