Grow Light Vs Sunlight (Which Is Better For Your Plants?)

These are your only two options.

Plants need light to grow and you have two ways of providing it: grow light vs sunlight.

Of course, there are many different types of grow lights.

We talk about all of that in a different article.

Today we are simply comparing grow lights as a whole with natural sunlight.

You may think that sunlight is obviously better for growing plants, but that is not usually the case.

Keep reading to learn why grow lights are often a better choice than sunlight. More importantly, we will help you figure out which option is the right one for you and your plants.

 

Grow Light Vs Sunlight

We will begin our comparison of sunlight and grow lights by looking at each light source individually, before comparing them directly. We’ll take a closer look at the advantages of each, before helping you figure out which makes more sense for your needs.

 

Natural Sunlight

While the initial answer may seem obvious, to a horticulturist, the sun provides much more than mere illumination. Sunlight is the portion of electromagnetic radiation emitted by the sun.

When growing plants, you should pay particular attention to the levels of infrared, visible, and ultraviolet light reaching your plants. Sunlight is the main player in photosynthesis, the process used by plants to convert light energy, in this case from the sun, into chemical energy.

While sunlight has provided the light for plants to grow since plants exist, it doesn’t reach all corners of the earth in equal amounts throughout the year. And it does have some additional disadvantages.

 

Grow Light

A grow light is an electric light source used by gardeners to help plants grow in lieu of, or in addition to, natural sunlight. Grow lights are designed to mimic the light from the sun or to provide a bespoke spectrum that aligns with the needs of the plants being grown.

Varying the color temperatures and spectral outputs from the grow light, and adjusting the intensity of the lights, allows us to imitate outdoor conditions. You can also typically adjust  grow light to suit the stage of growth and light schedule of your current crop of plants.

 

Similarities Between Grow Lights And Sunlight

Sunlight and grow lights are similar in several ways. The main way in which they are comparable is that they both help plants grow by stimulating photosynthesis. Both are light sources that your plants can use and feed off to grow.

In essence, a grow light is an artificial light source that is designed to mimic the sun’s light output.

Grow lights have improved over the years as the technology has moved forward. They are better than ever at producing beneficial light for your plants.

They are now capable of emitting a fully-adjustable full spectrum of light and are able to mimic the ranges of light that reach the earth from the sun.

 

Differences Between Sunlight And Grow Lights

One of the biggest differences between the two is their adjustability, or lack thereof. While the sun has consistently provided the planet with light for millennia, you cannot adjust it in any way.

You cannot move the sun closer or farther away. It has no dimmer switch. You cannot adjust the wavelengths of light emitted. And you cannot stop clouds from getting in the way and blocking it out. And then there are also the seasons to contend with, depending on where you live.

Grow lights, on the other hand, are much more adjustable. Not only can you set them up at different distances from your plants, but you can also adjust this distance as your plants grow and have different needs.

Most grow lights often also have a dimmer, which allows you to adjust the intensity of the light without moving them farther away or closer. And many grow lights (mainly LED grow lights) allow you to alter the type of light emitted, so that you can give your plants more blue light during the vegetative stage, then adjust it so they receive more red light once the flowering stage begins.

Finally, there is the obvious difference. Grow lights allow you to grow plants indoors, even in spaces completely devoid of any natural light. This is great for those with no outdoor growing space, or those trying to conceal their cannabis grow.

 

Advantages Of Sunlight

Perhaps the biggest advantage of the sun, especially in the current climate of spiraling energy bills, is that it is free! You don’t need to plug it in, and you will not be receiving a dreaded bill in the mail.

Another advantage of the sun is that, depending on where you live, there is a much lower chance of damaging your plants by giving them too much light and burning them.

Of course, if you live in the tropics, the sun can be very intense and potentially damage plants not used to such intense light. But in general, it’s less of an issue than it is with grow lights.

Another argument you could give for opting for the sun over a grow light is that the sun is safer in terms of being a fire hazard. While electric faults and user error can occur when using grow lights, which could lead to a fire breaking out, this is not an issue with the sun.

 

Advantages Of Grow Lights

The biggest advantage of grow light sover natural sunlight is that grow lights allow you to grow indoors. There are many reasons you may want to grow indoors and grow lights make that possible.

Grow lights are also more consistent and more adjustable than the sun. In terms of consistency, once your lights are set up and running, your plants will receive a consistent level of light that will not get blocked out.

The Sun has cloud cover to contend with. Depending on where you live, you may not even see it for a few days, or even weeks, at a time. While your plants will still receive light on cloudy days, much less will reach them.

You have probably already noticed that the sun is not always present in our skies either. While sun users see their plants plunged into darkness every night, grow light users can give their plants light 24 hours a day, should they wish to do so.

Due to the planet’s oblate spheroid shape, different sections of the earth’s surface receive different amounts of light too. The tropics receive the most consistent light levels, while areas far north or far south of the equator will see the ill effects of axial tilt on their light levels when winter rolls around.

 

Reasons To Use Natural Sunlight To Grow Plants

If you’re working within the constraints of a budget and are looking for the most cost-effective growing methods, then sunlight wins hands down. It’s completely free and abundant (depending on your location), and there’s no need for any additional equipment or energy consumption.

 

Reasons To Use Grow Lights For Plants

Being able to depend on the sun’s light is much easier closer to the equator. If you’re living in northern Europe, or the more northerly-reaching areas of North America, you will struggle to get enough sunlight at certain times of the year.

But if you use a grow light, you can give your plants exactly the same amount of light for 24 hours a day, seven days a week, all year long. For a price, of course.

If you are growing indoors, you will almost certainly want to use grow lights, unless your plants are in a room that gets a ton of natural light. Even with some natural light, adding a grow light to supplement it will result in a huge boost to your plants.

 

LED Grow Lights Vs Sunlight

As mentioned in the introduction, we are talking about grow lights as a whole today, and not comparing different types of grow lights. That said, LED grow lights are by far the best type these days.

They are also the ones that come closest to sunlight in terms of spectrum. But only if you get one with a spectrum similar to natural sunlight. With LED grow lights, you can get basically any spectrum you want.

Putting that aside, since good quality LED grow lights are the best type of grow light on the market, they compare the most favorably to sunlight. Everything said above goes for LED lights more than for any other type.

 

Is A Grow Light Considered Direct Sunlight Or Indirect?

In general, grow lights are not considered direct sunlight. But they can be if they are intense enough to burn plants. Also, UV light plays a big role in direct sunlight. If a grow light does not emit UVA and UVB radiation, it is not the same as direct sunlight.

Do plants need UVB or UVA light? They do not, but it can be beneficial in the right amounts. And it can be harmful if your plants are exposed to too much UV light.

 

Sunlight Vs Grow Light: Final Thoughts

When you compare grow light vs sunlight, the obvious difference jumps out at you: grow lights allow you to grow indoors. Moreover, they give you complete control over when your plants get light and how much they get.

This all allows you to give your plants exactly what they need when they need it, to maximize their growth and their yield. But grow lights do have one big disadvantage. They cost money to buy and run. And while some grow lights give you a great full spectrum light similar to sunlight, many do not.