Water, light and the week the frost arrives
A balcony is a harder place to grow things than a garden. Pots dry out in hours, the wind is stronger than it looks from indoors, and the light is whatever the building allows rather than whatever the plant wants. A phone helps with three of those: it can tell you what the plant is, remind you before it gets thirsty, and measure the light you actually have. The wind you learn by losing one pot.
The questions, and what answers them
| The question | What answers it | How reliable |
|---|---|---|
| What is this plant? | A photograph identifier | Good for common species, poorer for cultivars |
| How much light does this corner get? | A light meter app | Useful as a comparison, not a laboratory reading |
| When did I last water it? | A care app with a log | As reliable as your habit of logging |
| Why are the leaves spotted? | A diagnosis app, then your own eyes | A starting point, not a diagnosis |
| What is eating the leaves? | An insect identifier | Good at the common pests |
| Will it freeze this week? | A forecast with hourly minimums | Good for two or three days out |
| What can I sow now? | A planner with your climate set | Depends entirely on setting the location |
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What to install
Care schedules built around your actual conditions, with watering and repotting reminders that adjust to the season. The deeper features are a subscription, so see how far the free side gets you.
Planter. Plans a bed or a set of pots to scale, with spacing and companion planting, which is the part people get wrong with a tape measure.
A garden journal: what you planted, where, and what happened. Dull, and the only thing that makes next year better than this one.
Identification plus a care plan for what it finds, which suits somebody who has just been given a plant and does not know its name.
PictureThis. The most polished identifier, strong on ornamentals, with plenty of upsell around the edges.
PlantNet. Run by research institutions, free, and better than the commercial apps on wild species. Photograph the leaf, the flower and the whole plant for a confident answer.
Another research project, free and without advertising, and very good on European flora. Tiny download for what it does.
Plantix. Built for crop disease, so it is the one to try on spotted leaves and mildew. Treat the suggestion as a hypothesis to check.
Identifies the insect on the leaf, which decides whether you do nothing, wash it off or move the pot.
A grow light meter that uses the camera. Calibrated for the common phone sensors, so it is far closer than a generic lux app, and it makes the light problem visible.
Shows the sun's path over your balcony through the year, including how much the low winter sun is blocked by the building opposite.
The lighter version of the same idea, with an augmented reality view of where the sun will be in a given month.
Hour by hour temperature, including the overnight minimum, which is the number that decides whether anything needs bringing inside.
Wind on a balcony is the underrated killer of tall pots and young seedlings. This shows the gusts rather than the average.
Only relevant if you fit one of its timers or valves, and then it solves the fortnight you are away, which no reminder app can.
A photograph of the label, a note of where you bought it and when. The cheapest plant record there is, and the one people actually keep.
Photograph each plant on the first of the month from the same spot. Growth is invisible day to day and obvious across four photographs.
Working out what light you actually have
- Measure at the plant, not at the window Light falls away sharply with distance. A metre back from the glass can be a fraction of the reading at the sill.
- Measure at the same hour on a bright day and a dull one The range matters more than a single number, especially for a balcony that gets two hours of direct sun.
- Note which direction the balcony faces It sets the shape of the day: morning sun, afternoon sun, or bright shade all day, each of which suits different plants.
- Check what the building opposite does in winter A sun path app shows the low winter arc, which is when a balcony that was bright in June turns out to be in shadow.
- Match the plant to the reading, not the reverse Moving a plant into better light fixes more problems than any feeding schedule.
The three weeks that decide the year
Almost all balcony losses happen in three short windows: the first frost in autumn, a hot still week in summer when pots dry out in a single day, and the fortnight you are away. Everything else is routine. Set a calendar reminder a week before the average first frost in your area, and a watering plan before a holiday rather than after it.
- Remembering to water before the leaves droop
- Identifying what you were given
- Measuring light honestly
- Seeing a frost two nights ahead
- Keeping a record worth reading next spring
- Wind, which breaks stems regardless
- A pot with no drainage hole
- Compacted, exhausted compost
- A plant that is simply in the wrong place
- Diagnosing a disease from one photograph
Measure the light, log the watering, watch the overnight minimum in autumn, and photograph everything once a month. The plants do the rest.
Frequently asked questions
Are plant identification apps accurate?
For common species photographed well, generally yes. They are much weaker on cultivars and on a single leaf with no context, so photograph the whole plant, the flower and a leaf, and compare two apps when it matters.
Do light meter apps really work?
A camera based meter calibrated for phone sensors gives a usable relative reading, which is enough to tell a bright corner from a dark one. Treat it as a comparison tool rather than an instrument.
How often should I water?
No schedule survives contact with weather. Check the top few centimetres of compost with a finger and water when it is dry; use the reminder to prompt the check, not the watering.
Can an app tell me why my plant is dying?
It can suggest likely causes from a photograph, and it gets fooled by ordinary ageing and by watering damage that looks like disease. Start with light, water and drainage before believing anything exotic.
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