The question has a hidden second half. “Is my plant getting enough light” only becomes answerable once you add “enough for what plant, in what spot”, and almost nothing written on the subject adds it. So the advice arrives as a symptom checklist, and a symptom checklist can only tell you about a decision you already made some weeks ago.
There is a better order. Read the plant for what it is already telling you, then read the spot, then decide whether the two belong together. The rest of this page does those three in that order.
Worth a try
It can work here with a little care.
A little dim, but workable
Comfortable temperature
Humidity suits it
Airflow suits it
What the plant is telling you, earliest signal first
These are ordered by how soon they show up. The ones near the top are worth acting on. The ones near the bottom mean the plant has been short of light for a long time.
- New leaves are smaller than the old ones. Usually the first honest signal, and the easiest to miss, because nothing looks wrong. Hold a new leaf against one from last season.
- The gap between leaves is getting longer. Stem stretching toward the window is a light reading with a distance answer. The full version of what the stretch means is here.
- Everything leans one way. A plant that has to reach is telling you the light arrives from one direction and is not abundant enough to ignore.
- Variegation fades. Pale patches cost the plant energy to maintain. In dim conditions it reclaims them and goes greener.
- No new growth for a full season. By this point the plant is holding rather than growing.
- Lower leaves yellow and drop. Late. The plant is retiring leaves that no longer pay for themselves.
Notice what is missing from that list: any way to tell the difference between a spot that is slightly short and a spot that is hopeless. The plant looks the same in both cases for months.
The same six spots, three different plants
Here is what “enough” looks like when you hold the spot still and change the plant. Every one of these was scored by the same engine that runs the free checker on this site, with temperature, humidity and airflow set to each plant’s own preference so that the only thing varying is light.
| Spot | Estimated light | Snake plant | Golden pothos | Fiddle leaf fig |
|---|---|---|---|---|
| East sill, against the glass | 6,500 lux | Bright, still fine (68) | Ideal (100) | Ideal (100) |
| 1 m in from that window | 5,000 lux | Ideal (100) | Ideal (100) | Getting dim (68) |
| 2 m in | 3,150 lux | Ideal (100) | Ideal (100) | Getting dim (66) |
| 3 m in | 1,984 lux | Ideal (100) | Getting dim (68) | Not enough (46) |
| North sill | 650 lux | Ideal (100) | Getting dim (65) | Not enough (45) |
| 2 m in from a north window | 315 lux | Getting dim (68) | Not enough (46) | Not enough (45) |
Three things fall out of that table, and none of them survive being compressed into a single rule.
The brightest spot is not the best spot. The snake plant is at its best everywhere except the two extremes, and the east sill is one of the extremes. Moving a tolerant plant closer to the window is not automatically an improvement.
A fiddle leaf fig’s usable range is about one metre wide. Against the glass it is perfect. One step back it is already flagged. This is the plant people describe as dramatic, and the drama is mostly this.
The pothos covers most of the room and then stops. It holds from the sill to two metres in, which is why it has a reputation for surviving anywhere, and it still fails in the back half of a north room.
The light figures are estimates built from window direction, distance and typical clear conditions, not meter readings from your home. What travels is the shape: the fall is steep, and it is steepest in the first metre.
Why your eyes are the wrong instrument
Human vision adjusts continuously and hides exactly the difference that matters. We measured six spots in one ordinary living room on a clear day and the readings fell far faster than anyone standing in that room would guess: 20,000 lux at the window, 15,000 lux one metre in, 3,500 lux at two to three metres, 570 lux in the middle of the room, and 18 lux in the dark corner.
The middle of that room reads as a perfectly pleasant place to sit. For a plant it is about three per cent of the light available at the window. The full six-point measurement, with method and equipment, is here.
Two ways to read a spot before the plant does
The shadow test, no app and no equipment. Hold your hand about thirty centimetres above the spot around midday. A hard shadow with sharp edges means direct sun. A soft shadow with a readable outline is decent indirect light. A shadow you can barely find means the spot is dim, whatever the room feels like. The full shadow test is here.
A reading, if you want a number. A phone can be used as a light meter, laid flat and screen up at the height the pot will sit, which is a very different measurement from holding it at eye level and pointing it around. The ten-second method and its honest limits are here.
Either one beats waiting for a leaf to tell you, because both of them work on the spot before you commit a plant to it.
So what counts as enough?
For your plant in your spot, the only useful form of the answer is a comparison: this plant, that place, do they fit. That is the question the free checker on this site answers in about thirty seconds, without an install and without an account, and it says so plainly when it does not have enough information to answer rather than inventing a verdict.
If the answer comes back short, the fix is usually one of three, in this order: move the plant closer to the glass, move it to a different window, or change the plant. The third one is not a defeat. A snake plant on a north sill scores better than a fiddle leaf fig in the same place ever will, and it will look after itself while it does.
About this article
The scores in the table are estimates, produced by the same scoring engine that runs in the GrowSpot app and in the free spot checker on this site. Light was estimated from window direction and distance under typical clear conditions. Temperature, humidity and airflow were set to each plant’s own preferred range on purpose, so that the table isolates light rather than mixing four variables together.
The six-point room readings were measured, but modestly: a phone used as a light meter, laid flat at roughly pot height, same hour for every spot, one clear day, one room. Single samples rather than a study, and that room’s orientation was never recorded, so those figures are not offered as north or east window values.
The care baselines for all three plants come from our curated care data. Where a figure is an estimate we have said so, and where we do not have a reading we say that instead of filling the gap.
