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What Is Indirect Sunlight And Why Is It So Important?

If you’ve ever found yourself wondering what indirect sunlight is exactly, don’t worry, you’re not on your own.

To put it in the simplest terms possible, indirect sunlight is sunlight that is either filtered through a medium (such as a window or the leaves of a tree) or sunlight that is reflected off a surrounding surface.

What Is Indirect Sunlight

Here are some examples of where to place a plant that needs indirect sunlight:

  • An east-facing window 
  • A south-facing window that is shaded by surrounding trees or buildings throughout the day
  • Away from the window in a south-facing room

You might be wondering why these are the best positions for indirect sunlight. When you consider the species of the plants you have that need indirect sunlight, think about their natural environment.

With the exception of certain cacti and succulent plants, most commercially available houseplants would naturally be found growing on rainforest floors. 

When you think about these conditions, the sun is mostly blocked out by the canopy of leaves that the trees create. This canopy filters out most of the direct sunlight and absorbs the heat, leaving the rainforest floor with indirect sunlight

This is why you should only place a plant that needs indirect sunlight on a south-facing window that is shaded by surrounding trees or buildings throughout the day. 

The reason that the best place for a plant that needs indirect sunlight would be an east-facing window is that it will get a hit of sunlight first thing in the morning.

And, as the sun moves, the rays will still provide enough light but they will be reflected off surrounding surfaces instead of beaming down directly on the leaves all day long. 

If you don’t have an east-facing window, place your plants a little further back in a room that gets a lot of light throughout the day from a south or west-facing window. This will fill the room with light but, again, all of this will be reflected as indirect sunlight. 

Is a grow light considered indirect sunlight?

If you live in a particularly shady area and you’re not certain that you’re able to provide your plants with indirect sunlight, a grow light would be a good option.

A grow light can be considered as both indirect sunlight and direct sunlight depending on the power of the light and the settings you choose. However, most grow lights are better for plants that need indirect light as they simply can’t match the same power as the sun.

Is light through a window direct sunlight? 

By now, you should have a better idea of what indirect sunlight is. But when you fall in love with the next houseplant in your ever-growing indoor garden and you find that the care label says ‘direct sunlight’, what do you do? 

The immediate temptation is to put the plant straight on your windowsill. But, you better move that plant straight away because light shining through a window is not considered direct sunlight. 

The reason for this is that the light that shines in through your window is diffused and changes direction in a process called ‘refraction’. As this happens, the intensity of sunlight is reduced and, as a result, indirect light is created. 

So, while it may seem as though your lovely new plant is being bathed in sunlight, it isn’t getting the intensity it needs. 

This is understandably confusing as it stands to reason that your window sills are the best place for a plant that needs direct sunlight.

But, even if there is constant sunlight shining through the window, your plants will still only be getting around 50% of the direct sunlight they’d get if they were planted outside. 

Of course, in the case of houseplants, planting outside just isn’t an option. So, how can you make sure that you’re giving them the maximum amount of direct sunlight, even if it means some of it is lost through the reflections and filtering?

Well, it’s all to do with placement. There is an old gardening adage of “right plant, right place” and this applies to houseplants as well. Put simply, give the plant the best conditions possible and it will thrive. 

With this in mind, a houseplant that requires direct sunlight is best placed on a south-facing windowsill. You are still going to lose some of the light intensity, but it will be greater than any other window you can offer. 

If you don’t have a south-facing window, a west-facing window is your next best option. This placement will give you the most amount of sunlight after midday.

It will also give your plants prolonged exposure to warmth as the sun will continue to shine from this direction from midday right through to sunset. 

In both cases, it’s also important to make sure that there are as few barriers in the way of direct sunlight as possible. This could be things such as blinds, curtains, furniture, ornaments, and anything else that could potentially block out sunlight and throw a shadow across your plants. 

External barriers also need to be considered although these are usually out of your control. If you notice a tree or a surrounding building is creating shade, try raising the plant up on a platform to get as much sunlight as possible.

Some plants can also be suspended from the ceiling in special holders, giving you the ability to get them into as much direct sunlight as possible. 

Conclusion

So, there you have it, everything you need to know about indirect sunlight. The main thing to remember is that, when it comes to placing your plants in indirect sunlight, you have three options. 

An east-facing window is best. If this isn’t possible, place them in a south-facing window that gets partial shade throughout the day. And, if neither of these options is possible, place your plants further back in a south-facing room. 

In the instance where any of these options aren’t feasible, you could always invest in a grow light that will provide artificial indirect sunlight. It won’t be as strong as the real thing, but your plants will still be perfectly happy.