With the advancement of technology over mankind’s history, telling the average person from 500 years ago that we can grow plants simply with a glowing tube of glass would seem like magic.
And it really is.
With the large focus on sustainability and the environment, it would be unsurprising to hear grow lights coming up in conversations on all types of subjects.
Grow lights have become immensely popular, providing all sorts of alternative benefits as opposed to doing things the old-fashioned way. Talking about plant grow light bulbs can be unironically interesting, as there is so much to learn, so many different varieties, and the industry is in a constant state of evolution.
In this guide, we are going to cover the things you should know about grow lights, their purpose, the different types of lights and lots of other things.
Table of Contents
- An Introduction to Grow Lights
- A Brief History on Grow Lights
- Types of grow lights
- The Important of Light for Plants
- Full Spectrum LED light bulbs
- The Light Spectrum
- The History of Full Spectrum LED light bulbs
- Why use Full Spectrum LED light bulbs?
- Why Avoid Full Spectrum LED light bulbs?
- Why Use Full Spectrum LED Light bulbs?
- Other Types of LED Grow Lights
- Grow Lights in Action
- Other Things to Consider
- Grow Light FAQs
- What light bulb is best for growing plants?
- What Color Light is Best for Plant Growth?
- Can any light bulb be used as a grow light?
- Do full spectrum bulbs help plants grow?
- How much electricity do grow lights use?
An Introduction to Grow Lights
What are grow lights?
To put things simply, grow lights are quite literally just electric lights that are used to help plants grow. Originally, plant life would grow naturally thanks to the Earth’s sun. The sun’s rays are required for photosynthesis. Photosynthesis is not just a random word you heard in back high school science class - it’s the process that plants use to transform light, water and oxygen into carbohydrates (their source of energy).
Grow lights are more often than not going to be different from your regular lights; they usually will try to imitate the sun's light or they try to provide the ideal spectrum for certain plants. Some people use different temperatures when growing certain plants to help create the best environment for them.
The imitation of the sun is not always going to be a priority, because with a custom grow light setup you can create an environment that can be even better than something that can be found in the natural world.
For example, if you have plants that would benefit from vast amounts of sunlight - and a typical day doesn’t provide that - then you can create the most ideal setting for your plant thanks to grow lights.
So who might find using grow lights? All sorts of people.
Right off the bat, grow light bulbs for indoor plants has been increasingly used in farming. This allows farmers to grow large amounts of plants in a much more controlled environment, a lot of the time free from particular pests and other troubles that you may find when growing plants outdoors. A lot of people find a modern and futuristic appeal to growing plants indoors, especially thanks to the benefits of having them in such a controlled and monitored environment free from potentially harmful weather conditions.
Although grow light bulbs are obviously going to be highly popular with farmers, many people who live in highly urban areas may find it helpful to use grow lights for growing their plants indoors. Think of people who may be living in a relatively small apartment in New York City. There is basically no backyard for them to grow any sort of plant. Thankfully, a lot of people have made good use of using grow lights by placing their plants inside of a cupboard, for example.
A Brief History on Grow Lights
Mankind & Agriculture
So, where did this all start?
For a long time, humans were classed as “hunter-gatherers”. This means that their sources of food were obtained by foraging and hunting. Large groups of hunters and gatherers would travel long distances and often move where they lived in order to get food. Whether it be from hunting animals or picking berries.
This was because they were unaware of the fact that seeds can be used to grow plants, infinitely.
This discovery led to the “agricultural revolution”. This was a huge turning point for the entire history of humanity because it meant that we were no longer required to relocate and continuously take from the environment.
This fundamental change meant that cities were able to happen, and large groups of people were able to stick around and repopulate even faster. Dying from starvation was less likely because of the fact that humans could regrow food instead of hoping to find some.
The Invention of Grow Lights
Since the 19th century, electric lights have been used to grow plants. The Russian botanist Andrei Famintsyn is often regarded as the first to use artificial light to help plants grow.
Incandescent light bulbs are often agreed upon as being the first type of light bulb to be used as grow lights. They are also one of the first light bulbs to be invented, famously thanks to the great Thomas Edison. These lights work by using electricity to heat a wire filament, making it glow.
Fluorescent lights were the second generation of grow lights. These types of lights were invented around the 1920s - 1930s. They make use of gas in order to light the bulb; electricity runs through it, which excites a mix of gasses. They soon became far more popular than incandescent bulbs because they were more energy efficient, lasted longer and had an appealing brightness to them.
The third generation of grow lights is considered to be High-intensity discharge (HID) lamps.
Fluorescent lights were taken over in popularity by HID lamps. These lights have a high amount of efficiency, thus reducing the cost which was a big benefit for their use. A few of these lamps produced a nice spectrum of color that is similar to the sun, which was what made them so popular. “Mercury vapor” lamps were some of the first used HID lamps. They started to trend as they were used for street lighting. One of the drawbacks was that they had a pretty poor spectrum for the growth of plants.
Common HID lamps work by filling arc tubes with gas that contains metal/metal salt like mercury and flowing electricity through tungsten electrodes. The arc heats up the metals and produces a very bright light.
Finally, the fourth generation of grow lights involves LEDs (Light emitting diodes)
LED grow lights make the highest amount of photosynthetically active radiation out of any light.
This means that they are very good for growing plants, because of the similarity they share to the sun’s radiation. LEDs create light because of electricity passing through what is known as a semiconducting material (which is the diode). Photons get emitted as a result (creating light).
LED lights are some of the longest-lasting and most efficient types of light available. By far, LED lights are one of the most commonly used lights ever. From electronics to toys, they are very accessible and functional. Grow light LED light bulbs are by far the latest and greatest.
Types of grow lights
Everyone is going to be aware of the fact that artificial lights can come in many different shapes and sizes. In these next few paragraphs “types” of lights will be referring to the different shapes and designs of lights. When learning about grow lights, it's good to know that there are different types of lights that are going to be preferred by different people.
Light “bulbs'' are probably the first thing that pops into someone's head when thinking of a light. These are typically in the bulb or circular shape and are small. The best grow bulbs for plants don’t have to break the bank - as bulbs are one of the cheapest types of lights.
Grow lamps are usually going to be similar to what you would think a regular lamp is. But in the world of grow lights, they are usually longer, and are held up by a sort of support or are hanging. The one thing to note is that they are going to be bigger than just bulbs.
Most of the time, tube lighting is going to be associated with fluorescent lights (although that is not always the case). These are long lights that are used in setups that have rows of plants.
Fixtures are quite similar to lamps. They are also similar to what comes to mind when you think of a regular light fixture. They feature lights fixed to a body and are often some of the biggest types of lights used in setups.
The Important of Light for Plants
It is well known that light is essential for the growth of plants. But why exactly do plants need light?
This is one of the most important things to learn about when getting started with grow light bulbs. Understanding why plants need light and how they transform it into energy can help you make the most out of your setup.
There’s that word again. But it’s really important.
As mentioned before, photosynthesis is a process used by plant life. Without anything sounding like a biology lecture, photosynthesis is the backbone of how plants work - it is how they create their energy. Water, carbon dioxide and most importantly light are required for photosynthesis.
First off, carbon dioxide is absorbed by the plant's leaves. Sunlight will then break up the compound. Water and air mix with this, in turn creating glucose. The glucose molecules will then start to stick together and make carbohydrates - which is what the plant will use for energy.
How Much Light Do Plants Need?
Obviously, this is going to vary depending on the plant. But before you start using grow light light bulbs to grow your plants indoors, start by trying to figure out how much light your plants are actually going to need.
If you are going to be growing some indoor plants that will not be receiving natural sunlight, then around sixteen to eighteen hours of light are going to be necessary. If you happen to have plants that will receive some light then look for around 12 to 14 hours. Try to use light for around the same amount of time that plants will receive it during the day.
If you are a perfectionist and are unsure how much light to give to a plant, the best thing to do is to research it. However, it is not unusual for beginners to just simply try to replicate the amount of light their plant would receive in the natural world.
Grow Lights Compared to The Sun
It is simply a fact that sunlight can be better for plants compared to using artificial light. This is because the sun is a lot more powerful than grow light bulbs. Plants, being a natural occurrence on Earth, are also more accustomed to the sun since this is how nature works. The universe’s creator pretty much intended for plants to grow outdoors in nature, rather than with artificial lights.
But don’t let this throw you off. There are so many benefits to using grow lights too. Thanks to the technology we have in the modern world, some lights can be almost as good as sunlight!
Light comes in a whole spectrum of different colors. Plants require different types of light too, red and blue light specifically. The red light will help plants create fruit and flowers, and blue will help the growth of leaves. Sunlight, on the other hand, provides the entire spectrum of light. The majority of typical light bulbs will only produce yellow or green light, while others may be used for red or blue light. A lot of grow lights are now designed to cover the entire spectrum.
Full Spectrum LED light bulbs
How about we take a look at different types of grow lights now? The best type of grow light is more often than not going to be full spectrum LED grow light bulbs. Compared to other grow lights, full spectrum ones are going to be closest to the sun, and since they are LEDs there are a lot of benefits that come with using them.
The Light Spectrum
One thing to keep in mind is that full spectrum lights are still not identical to the sun, although the light emitted from them is still relatively close.
Now, we know what light is important for plant growth. But what exactly is light? Well, light may be something that is visible to the eye, but there is an entire spectrum that we cannot see. All this can be found on the electromagnetic spectrum. Everything from gamma rays, x-rays, ultraviolet rays, radio waves and so on can be found on the electromagnetic spectrum. The waves of light are measured in nanometers, and we can only see a very small portion of this which is classed as “visible light”.
Plants are mostly going to respond to wavelengths of light from around 400 to 700 nanometers. This is for their photosynthesis, thus why the light within that spectrum is also known as PAR (photosynthetically active radiation).
The History of Full Spectrum LED light bulbs
Full Spectrum LED light bulbs are one of the most recent inventions in the timeline of lights.
At first the term “full spectrum” just meant the only source of real full spectrum light - which is the sun.
After a while though, the term started to mean other characteristics of sunlight. At one point, the lighting industry started to use the term “full spectrum” to refer to lights that create a CRI (color rendering index) above 90.
The human eye can see colors much more precisely when there is a light source with a CRI above 90, because of how we also see colors in nature thanks to the sun’s light.
When growing plants indoors became more popular, a lot of lights being sold began to use the term “full spectrum”.
Why use Full Spectrum LED light bulbs?
One of the most obvious reasons why people decide to use full spectrum LED light bulbs is the fact that compared to other types of grow lights, they allow a better spectrum of light that is ideal for plants. As mentioned before, LED lights last longer and also require a bit less energy.
Why Avoid Full Spectrum LED light bulbs?
Although these types of plant grow bulbs are great, they are a couple of little drawbacks to keep in mind.
First of all, they aren’t exactly “optimized” for plant growth. As mentioned earlier, plants only really photosynthesize light on the 400 - 700 nm wavelength. (Remember PAR). So this basically means that they don’t exactly care about how “bright” a light setup is. The whole idea of using bright lights is for an aesthetically pleasing setup.
One of the only other problems with these lights is also that they aren’t really dynamic like the natural sun. Some plants respond better to a natural shift in light over time, and different internal processes in the plant get activated depending on the amount of light from one waveband relative to the other.
Why Use Full Spectrum LED Light bulbs?
There are lots of different reasons why indoor farmers will want to use full spectrum LED grow lights.
First of all, plants don’t actually really need the entire spectrum that the sun emits anyway. In an indoor setting, the plant is in a more controlled and relaxed environment which means that it isn’t at risk for environmental problems or other species.
Full Spectrum lights are also one of the most aesthetically pleasing grow lights that are available.
And again, as LED plant light bulbs they are very powerful while remaining energy efficient, environmentally friendly and long lasting.
Because of how new they are, they are currently some of the most advanced grow lights that you can find on the market.
Other Types of LED Grow Lights
Full Spectrum LED plant bulbs may be the latest and most popular, but it is good to know that there are also other types of LED grow lights such as:
- Narrow Spectrum LED Grow Lights
- Broad Spectrum LED Grow Lights
- Adjustable Spectrum LED Grow Lights
Basically, the name implies what each LED grow light can do.
Narrow spectrum lights are good for greenhouse environments and are optimized for the PAR wavebands. Broad Spectrum lights are white, being a mix of red, blue and green wavelengths. Lastly, adjustable spectrum lights allow a lot of control as their spectrum can be adjusted - like how the sun is dynamic.
Most grow lights are now focused on the benefits of LED lights. Fluorescent lights can be helpful during the seedling stage and when a plant is just starting to grow. They used to be the number one light to use, after being taken over by LEDs. Fluorescent lights don’t really allow as much of a wide spectrum of light like LEDs either
Halides Grow Lights
Metal Halides are part of the HID lamp family, and have been around since the 1960s. They are often said to be good for vegetable growth, however they can also produce a lot of heat.
Incandescent Grow Lights
You may have picked up from before: Incandescent lights are one of the oldest types. They are also notorious for being one of the most unsuitable options you could use for grow lights. They’re not really energy efficient, do not last long at all and produce way too much heat for plants. Most indoor farmers agree that people should avoid using incandescent lights and try to stick with something better.
Grow Lights in Action
Ok, now let's have a look at how we actually use grow lights for indoor plant growth. A lot of the time you can end up confusing yourself if you think too far into it, so we are going to explain things in a straightforward manner and also have it based on what is most commonly performed.
Different plants need diffrent grow lights?
More often than not, you can get away with using the same grow light for a variety of plants - as long as it is a good one. Remember that the sun is the sun - and all plants are naturally dependent only on the light that it emits. It is usually more important to actually focus on the distance between your plants and the grow light…
Grow Light Distance
This is one of the most important factors - how far should my grow light be? One of the main reasons this is so important is because of the heat. Plants don’t like when things get too warm.
For incandescent lights, you’ll want to keep them the furthest away from the plants. At least 24 inches away is best. If you use fluorescent lights, think at around 12 inches away since they create less heat. For LED grow light bulbs, they can be the closest - only 6 inches.
Grow Light Duration
Another important question that thankfully gets asked a lot is how long to leave the lights on. Again, it is better to look into how much light your plant individually needs. But as a rough guideline: 12 to 16 hours are needed for vegetables and flowering plants. You’ll also want to try and give them at least eight hours of darkness.
Plants getting darkness is important for their biological cycles. In the darkness, plants will break down energy for their growth and flowering.
Other Things to Consider
Using grow lights is fun, and at its core is a pretty straightforward task. There are just a few other minor things that you should consider before you dive into it.
What Plants You're Growing
This has been mentioned a few times, but it is really good to look into the individual needs of each plant. Some plants perform better with less light, less duration, etc than other plants. A quick Google search should do the trick in helping you figure out the needs.
How Tall Will The Plant Get?
An amateur mistake is forgetting that certain plants grow really tall and need a lot of space. For example, a mistake would be seeing a long and tall vine-like plant completely grow all over the entire setup, past the lights.
Always plan out your space, and try to imagine how things are going to look when the plants grow.
Setting Up Your Indoor Area
There’s a few things to consider when setting up your indoor plant area. First things first: Is it going to be big enough? Just always remember if your space is going to give enough room for plants to grow, both sideways and up.
A popular spot that a lot of beginners decide to use is places like a cupboard or even a closet. These aren’t even bad ideas either.
Grow Light FAQs
What light bulb is best for growing plants?
The best lightbulb for growing plants is going to be LED grow light bulbs for indoor plants. These lights produce low amounts of heat, which are good for plants. They also have the ability to cover a nice spectrum of light and be energy efficient and long lasting.
What Color Light is Best for Plant Growth?
Overall, plants respond best to light on the wavelength of 400-700 nanometers. Red light is good for budding and flowering, and blue light is good for chlorophyll absorption and photosynthesis.
Can any light bulb be used as a grow light?
Technically, light is better than darkness for plants - but you will see such a difference in results when using proper light. Full spectrum LED lights are some of the best you can use for indoor plants.
Do full spectrum bulbs help plants grow?
Yes, definitely. Full spectrum grow lights provide light within the spectrum that plants respond to the best. Full spectrum bulbs try to imitate the sun’s natural power.
How much electricity do grow lights use?
It really depends on the electricity cost in your area, but the best thing to keep in mind is that LED lights are by far the most energy-efficient, while fluorescent lights are around second place. Incandescent bulbs are some of the least efficient forms of light.
Getting into indoor farming doesn’t have to be expensive. It’s also actually pretty easy to learn and is a very fun thing to do. The best thing? You get to see life grow before your eyes, and even have the chance to have your own food!