If you’ve bought a houseplant, read a houseplant book or a blog or even just had a look around the garden centre you’ve no doubt come across the term ‘Bright Indirect Light’. But what is bright indirect light?
Good question.
The answer isn’t quite what you might expect by taking the phrase literally.
My definition of bright indirect light is:
A position where your plant will be able to see a good portion of the sky, but will only ever receive direct sunlight between 0-4 hours in a day.
So it’s not always going to be strictly ‘indirect’ light. For an explanation of this, and other light conditions, read on.
Houseplant Light Conditions
Let’s have a look at the light categories you will usually read on the side of a plant pot.
- Direct Light
- Bright Indirect Light
- Medium Light
- Low Light
Do you think you could describe the light in all the parts of your home with just 4 categories?
Let me answer for you, seeing as this is a one-way conversation. Sorry about that! 
No, you can’t possibly accurately describe light conditions all over your home with just 4 categories. This means that these categories are intentionally vague.
When a houseplant grower slaps a label on their plant, they want to give you a bit of an indication of where it will be happy. This is still very useful information as long as you know what it means.
Direct Light
Defining the other categories becomes a lot easier once you know what bright indirect light means.
Direct light covers all the situations where your plant can see a good portion of the sky and will receive direct sunlight for over 4 hours a day.
Within this category there will be plants that are on the lower end of the light scale and those that are higher. For example, cacti an succulents like to be in the sun all day, whereas a snake plant will love some sun, but not a whole day.
Bright Indirect Light
As I’ve already described, bright indirect light covers areas where your plant can see a good portion of the sky, but will only receive direct sunlight for between 0-4 hours.
There are a couple of things in here to unpack.
Why does it matter that the plant ‘sees’ a good portion of the sky?
You don’t need sunlight falling on you to receive a large amount of light from the sky. Within the atmosphere, light from the sun bounces around and diffuses over the whole world. This is why a North-facing window, completely hidden from the sun, can still let in a lot of light.
If your plant can ‘see’ the sky, and a good amount of it, then it will still be receiving a lot of light.
But what about the direct sunlight for 0-4 hours? Surely that means it is getting direct light? This goes back to the fact that these categories are intentionally vague. Bright indirect sunlight is just a name for the category of light below direct light. There will be some overlap.
In addition, your plants will tolerate a range of conditions.
Medium Light
Medium light is when your plant can see very little or no part of the sky. There will be no direct sunlight. If your plant cannot see any sky but is still near a window then it will be getting medium light.
In a space that is getting medium light, you probably wont feel the need to turn a light on.
Low Light
Low light is when your plant cannot see any sky, it is not near a window and you will probably feel the need to turn a light on to enjoy the space yourself.
There are some plants, that will ‘tolerate’ low light, even survive for years in it, but if we’re being completely honest, it’s not good for them in the long term.
Light is what feeds a plant and if there is little light, it will not grow well. In addition, when a plant is receiving plenty of light, it will soak up more water to use in the photosynthesis process that turns light into food. If it isn’t getting much light then there is a risk that it will be sitting in water too long and the roots can start to rot.
As you can see, even a description of each category of light for houseplants leaves things a bit vague. This is why I like to get a bit more scientific, especially with light which is by far the most important factor in houseplant care.
Measuring Light
If you’re serious about caring for your plants, then getting the light conditions right is your first port of call. To do this, it’s best to have a way of measuring light accurately.
I use a dedicated light meter to get readings of light in different positions in my home, as well as at different times. They’re not expensive, certainly by comparison to losing a few plants because they were not getting enough light!
A light meter measures light in ‘foot candles’ which gives me a hard-and-fast way of knowing exactly what level of light a certain position is getting.
There are so many factors that can influence the exact levels of light at a certain spot.
- Amount of sky/sun visible.
- Objects outside blocking a window.
- Window dressings.
- Objects inside blocking light.
- Reflective/unreflective surfaces.
The only way to truly know how much light a plant will get is to measure it with a light meter.
Using a table of ideal conditions for different houseplants, I can then see what plants will do well in a certain position or, if I want to get a certain plant, I can see which parts of my home are best for it.
If there is nowhere suitable in my home for a plant, then I might not even get it.
This is a very different way of thinking about plants than ‘which plant will work with my decor?’
The be a great houseplant gardener, you’re going to have to put the plants first and where they look the best second.
So, what is bright indirect light? I’ve given you the definition but hopefully opened your eyes to the fact that you can’t rely on one definition to ensure that your plant is being given enough light.
Houseplant care isn’t easy, but it doesn’t have to be complicated. My aim is to make it as accessible as possible to everyone, while making sure the plants thrive.