Growing plants without sunlight used to be an impossible feat. Can you even imagine how hard it is to maintain growing plants during the winter months? Plants that are allowed to cultivate without sunlight often become tall but elongated and “leggy” in appearance. Their leaves also turn paler and paler each day they don’t receive adequate sunlight.
While most people may not have in-depth knowledge about botany, it’s not a surprising fact that plants need sunlight to live and thrive.
Plants have the unique ability to make food for themselves. But they’ll need the sun’s energy to create sugars that will join with water and carbon dioxide to form their food. This process is popularly known as photosynthesis (1).
Try watering a plant and diligently adding fertilizer to its soil for a few days. But you must not expose said plant to sunlight, even for a few minutes. Chances are this plant will still be unable to initiate photosynthesis, despite the presence of water and fertilizer, to make its own food. Hence, the result is a starving plant that’s a few days down to its demise.
So now, we’ve seen how important sunlight is to plants. But going back to the topic at hand: Is it really possible to grow healthy plants without sunlight today? Well, the answer is a big yes, all thanks to grow lights.
Grow lights are artificial light sources which emit ultraviolet rays in an amount adequate enough for photosynthesis to start. In short, grow lights are electric lights that serve as a safe yet effective substitute for sunlight.
The use of grow lights for plant growth was first discovered in 1868 by a Russian botanist named Andrei SergeyevichFamintsyn. Since then, light-filled grow lamps not only illuminated the plants when there is a lack of sunshine in the area, but they also serve as great instruments for researches on plant life, growth, and metabolism.
Grow lights are made up of varying lamp colors and intensities to help mimic outdoor spectral outputs and temperatures. This is to suit the ever-changing photoperiod needs of plants growing at incremental stages of cultivation. Certain reflectors are also being used to hasten the effects of grow lights on plants. These reflectors help improve the efficiency of light and help create equal plant growth within a greenhouse.
Most grow lights are used to cultivate plants on a commercial level. They are especially useful for plant propagation, horticulture, indoor gardening, and mass food production. But did you know that you can also create a DIY version of grow lights for your very own garden?
Creating your own grow light system enables you to grow your favorite plant foods every single day of the year in your own yard. You can harvest your fresh produce straight from your own garden if you use grow lights to cultivate your plants even during the harsh winter months. And since you’re able to control various environmental factors in your indoor garden by using your grow light system, you can be confident that your garden will have a good survival rate.
Perhaps you’re thinking that a do-it-yourself grow light system is hard to set up, control, and manage. Not to worry, because that is totally not true and we’re also here to help you. Setting up your very own grow light system is pretty much a simple process when you’ve got the right tools at hand.
Ready to learn more about grow lights and how to make them? Let’s dive right in.
Parts and Tools
To start off, let’s look at the general parts of a grow light and the tools we’ll be needing to create our own.
There are four main parts of a simple grow light:
This is no doubt the most important part of a grow light. The lamp is the source of illumination and heat, which is what indoor plants need to thrive and grow properly.
Ideal lamp types vary depending on the type of plants that will use them. There are several types of lamps that you can choose from.
- Incandescent lights
- Metal Halides
- Fluorescent Lamps
- Compact Fluorescents
- Light Emitting Diodes
- High-Pressure Sodium lights
- Sulfur Plasma Grow Lights
These types of grow lights will be further discussed in the next section.
2. Electrical Light Ballast
Ballasts are the heart of the lighting system’s electrical component. It controls the light currents and is often connected to a cord plugged into an electrical outlet. Ballasts also ensure that the system is using the proper voltage as soon as it starts working.
These are hood-like equipment that is placed next to your grow light’s lamp. The light emitted by lamps tend to be scattered, so reflectors are needed to direct the light flow right over your plants.
A quick overview of the various reflector types includes the following:
Air cooled reflectors
These are reflectors attached directly to a separate cooling system that helps control humidity levels inside the room. These reflectors are best suited for tight spaces like grow tents and small grow rooms.
These are inexpensive reflectors that direct the heat from a grow room outwards so that it can be removed by a cooling system. Three examples of these reflectors include wing reflectors, parabolic reflectors, and standard fixtures shaped like a hood. Non-air-cooled reflectors are good for beginners and for grow rooms with larger spaces.
These are special reflectors made exclusively for use with compact fluorescent light lamps.
The grow light stand is a structure wherein the lights can be suspended and the plants can be placed underneath. Stands vary in size and materials used. Wire stands are the most commonly used in home grow rooms and large greenhouses. Stands made of wood and heavy-duty plastics are also other options.
Now, let’s move on to the tools we’ll need to build our own grow light system. You won’t need much, just the following basics:
- Wire cutters
- Soldering iron
Types of Grow Lights
Deciding on which type of grow light to use will greatly depend on its efficiency in energy consumption and photosynthesis capabilities. Before we move on to the types of grow lights, let’s understand first what kinds of light spectrums a plant typically absorbs in order to grow and thrive well.
Plants use light within the range of the spectrum that is visible to humans (2). Think of this as the colors visible to humans when a rainbow appears in the sky. But plants also need light from higher and lower wavelengths, which include ultraviolet and microwaves, respectively. These types of light are especially needed during the crucial stages of the vegetative, blooming, and fruiting phases.
Color temperature is a concept used to explain the light spectrum needed by plants to fully grow using grow lights alone. Kelvin (K) is the measurement unit used to indicate color temperature.
Grow lights that can provide a full light spectrum are typically within a high color temperature range of 5,000-6,500 K. These types of lights emit bluish tinges and have an overall positive impact on vegetative growth.
Lower color temperatures are often within the 2,500-3,000 K range. Lights falling in this category emit a reddish tinge. Some lights even have a yellowish glow to them. Grow lights with lower color temperatures are great for the blooming and fruiting stages of plant growth.
Now that we have a background on the color temperatures emitted by different grow lights, let’s take a look at the several types of grow lights available in the market today:
Incandescent bulbs work by heating up a filament to produce heat and light. This is actually the original light bulb type that was introduced by Thomas Edison in 1879.
This type of light is technically not considered as a grow light, given that it emits 90% of heat and only 10% of light. However, it is still marketed and labeled as one. And several people are able to utilize incandescent bulbs as a supplemental lighting source for small house plants.
Incandescent bulbs have a low color temperature of approximately 2,700K. It has a lifespan of around 750 hours. These bulbs are best suited to plants with minimal light requirements like ferns, dracaenas, and vines. It’s also good as a secondary source of light for larger grow rooms.
High-Intensity Discharge Lights
If you are in need of main grow lights that are strong enough to fire off ample growth of several indoor crops, then you can consider using a High-Intensity Discharge (HID) grow light.
HIDs are made up of glass-filled tubes where electricity is passed through to generate light and heat. HIDs are similar to incandescent bulbs in that they generate a lot of heat, but they are still a more efficient choice.
HID lamps are the most commonly used grow lights by large-scale indoor farmers and professional horticulturists. These growers often use one type of HID lamp or use a combination of the two lamp types, depending on their needs.
There are two types of high-intensity discharge lights:
This is an HID lamp which largely resembles Mercury Vapor Lamps. However, they have plenty of additional metal halide compounds on the bulb’s tube, which serve to improve the lamp’s color rendition and light efficiency.
The light emitted by metal halide lamps tends to lean more on the bluish tinges, making it a good choice for growing a wide variety of plants in the vegetative stage. It boasts of a full spectrum of color temperature and has an average life span of 10,000 hours. A wide range of food crops benefits greatly from metal halide lamps, including tomatoes, spinach, lettuce, peppers, and flower crops.
High Pressure Sodium (HPS) Lights
This type of HID light is a low-color temperature lamp which emits reddish and yellowish tints at 2,200K. As HPS lights lean toward the low side of the color spectrum, they are perfect for the flowering and fruiting stage of crops. It has a lifespan of 10,000-18,000 hours.
The commercial greenhouse industry heavily relies on HPS lights as a supplement to natural light to power their crops’ growth and development. The lights often hang way higher than usual from the crops, not only because they are only used as secondary light sources, but also because they become hot fast and may run the risk of burning the crops when placed at nearer distances.
The long tube-like lamp bulbs we are all well-familiar today are actually fluorescent lamps. Ordinary fluorescent bulbs are used to grow plants with low to medium light requirements. Bulbs that are narrower often produce more light and have a full spectrum of color temperature, which is highly ideal for growing plants like herbs, starter plants, cattleya orchids, and carnivorous plants.
You can choose from the following types of fluorescent lamps:
Standard T2 Fluorescent Lights
These lights are powerful as they carry a full spectrum of color temperature. They are best used for starting to grow seedlings. They have an average lifespan of 20,000 hours.
High Output T5 Fluorescent Lights
High Output fluorescents are a good choice as a primary light for indoor plant growth. They emit double the light generated by standard fluorescent lamps. They are available in two color temperature ranges: low range at 2,700K and high range at 6,500K. Its availability in both ends of the color spectrum makes it a great choice for all stages of crop propagation. Average lifespan approximates at 10,000 hours.
These are smaller versions of High Output fluorescent lights with a wide variety of wattage use. They are available in color temperatures of 2,700K for low range, 6,500K for high range, and 5,000K for full spectrum. 10,000 hours is its average lifespan. These lights also have special reflectors to direct light towards the plants. Compact fluorescents are widely used for growing indoor houseplants, carnivorous plants, and phalaenopsis orchids.
Light Emitting Diodes (LED)
LED lights are a popular choice for home grow light lamps because they save energy by emitting only the colors that plants can absorb – blue and red. They are also highly compact, efficient, and lightweight. They don’t come cheap up-front, but several plant growers prefer them because they can save up on operational costs in the long run.
A unique feature of LED lights is its ability to emit light wavelengths that correspond to the plant’s respective chlorophyll production peaks. They also do not need reflectors because they directly emit the light to plants without the light being dispersed to other places.
LED lights have an amazingly long average lifespan of up to 50,000 hours and above. It maintains an efficiency rate of more than 50% even when used for long periods of time.
LED lights can be used as a stand-alone grow light or can be combined with any HID type lamp as a secondary light source. They can be used throughout the entire crop propagation stages, from the vegetative to the blooming and fruiting phases.
Sulfur Plasma Lights
The newest lamp type to enter the grow light industry is the sulfur plasma light. Sulfur plasma lights are quite pricey today because of its unique characteristics.
It is unique in that it is the only lamp type that emits light through microwaves. This light is also thought to have the capacity to emit light wavelengths and frequencies that closely resemble those emitted by the sun.Ongoing researches such as this one conducted by Japanese researches are trying to tap into the possible characteristics of sulfur plasma lights (3).
How to Install Grow Lights?
By now, you have probably picked out a grow light that will perfectly suit your indoor home gardening needs. But how do you properly install them? Here are tips and considerations to keep in mind when installing grow lights.
Follow the Inverse Square Law.
The Inverse Square Law is a principle that guides plant growers and horticulturists in efficiently installing their grow lights. It’s actually a simple rule: Wasted light is inversely proportional to the distance of the grow lights from the plants. The amount of light lost or scattered to other places becomes larger as the lights are suspended higher and higher from the plants.
Doubling the distance from your plants to your suspended light source will yield ¼ of the light amount that you initially started on (4). Hence, the higher your light source goes, the less amount of light and heat your plants will receive.
Don’t think that you need to suspend your lights low thinking that it’s the best way to maximize the lamp’s effects. Keep in mind that plants in a natural environment receive their light from the sun, which is several million miles away. Grow lights have frequencies and wavelengths that are heaps lower than that of the sun. But then, these lights still have the potential to burn your plants when placed too close because of the heat generated by electricity. Hence, you must determine the best height for suspending your grow lights based on your crops and your lamp type.
Space your plants accordingly.
How much planting space do you have? Are your plants located on a basement area, an entire room, or on shelves of a home-made grow light system? It is important to know all these so that you can space your plants properly.
Arrange your plants into even spaces, taking into account your pot size, plant size, and plant type. Usually, it’s a sound idea to place pots or trays 4-8 inches apart to give them ample space for growth and daily care.
Spacing your plants evenly is important before installing your grow lights because you’ll have an idea on how much space and light your grow lamps need to effectively cover. You can also base the height of your grow lights installment on how densely packed your plants are throughout your gardening area.
Calculate the number of bulbs you’ll need.
Wattage is an important factor in determining the number of light bulbs you will need. Edible plants typically require 40-50 watts per square foot in order to yield quality fruits and vegetables.
Here is a simple calculation to learn how many bulbs to install: Multiply the number of watts you want to give your plants by the size of your growing area in square feet. Then, divide the answer by your preferred lamp’s bulb wattage. You can easily find the wattage on the bulb’s packaging.
The final answer would be an estimate of the number of bulbs you have to install.
Determine the right height for the grow lights placement.
Lighting levels will depend on several factors. Hence, it can be hard to indicate a one-size-fits-all height for grow lights placement. Determine first the following:
- Plant variety you’ll cultivate
- Number of plants to place on your grow light system
- Plant density and spacing
- Any special growing considerations your plant may need
- Type of grow lamp to be used
Do some research based on the plants you want to cultivate. Always keep in mind that grow lights have the potential to cause hot spots and heat overkill to plants, so plan your lights placement well.
Make sure your ballasts, circuit boards, and other electrical components are properly working.
Piece together the components of your grow light and test them to see if they are properly working before mounting the lights over the plants.
LED light panels might require circuit boards before you can install them. If you will be working with modular circuit boards, wire and solder together the parts securely according to a circuit diagram. You’ll typically be working with resistors that are pieced together with USB cables to light up all the LED lights in a panel.
Also, ensure that the area where your plants and grow light system has readily-accessible power outlets where you can easily plug your lights.
Install your grow lights securely.
Once you’re done with the electronics and the measurements, you can now install your grow lights above the plants.
Position the lights at the proper height you’ve previously determined. Lock them in place via screwing or wiring, or follow the lamp manufacturer’s recommendations for installing them properly. You can then add the reflectors, ventilation system, and other accessories you wish to use after the lights have been in place.
You have to adjust the height of your grow lights as your plants grow and enter the different stages of propagation. Make sure that your installation is secured yet flexible enough to let you readjust the lights as frequently as needed. Using metal chains or pulley systems to hang your fixtures on its support rack are great for that flexibility you need.
How Long Should I Run Grow Lights for Everyday?
Optimal plant growth isn’t entirely dependent on the amount of light it receives. There must also be a period of darkness for plants to rest and recover. The principle of photoperiodism explains this well.
Photoperiodism is a term used to describe how plants respond to the lengths of both light and dark periods (5). This is crucial for the plant to determine their flowering times. Flower-bearing plants actually contain unique proteins that sense changes in seasonal light levels (6).
Blooming times are not the only plant activity affected by photoperiodism. It also affects roots and stems growth, as well as leaves shedding during a change of seasons.
Plants need some time in the dark to process the energy they collected from photosynthesis during the day. They ramp up their growth and flowering abilities as they take a break from photosynthesis in the darkness. Just like humans, plants also need a quiet time to relax and breathe.
This is why the length of time a plant is exposed to darkness is as important as the times the plant is underneath a light source. Plants do need darkness to help them grow, bloom, and bear fruit.
Which is why as a general rule, you should turn on and off your grow lights during these recommended times:
- 12-16 hours of light per day for vegetables
- 16 hours of light per day for flowering plants
- At least 6-8 hours of darkness per day for all types of plants
If you want to be extremely precise on the light and dark requirements of your particular crop, you may consult your local nursery or you may check your plant tags and seed packaging.
It helps to add timers to your grow lights so that they automatically turn off after a set number of hours has passed. Automatic timers are especially useful for when you are busy and have the tendency to forget the right hours to turn off your grow lights. Several light timers are available on the market today and are compatible with almost all kinds of grow lamp types.
Warm Vs Cool Light for Grow Lights
We have previously covered color temperature a few paragraphs back, but let’s do a quick recap here. After all, this is the foundation behind warm and cool grow lights. And this is also extremely crucial to the success of your indoor farming ventures.
In a natural farming setting, sunlight emits rays that get directly absorbed by the plants. These rays include both ultraviolet rays and microwaves. Ultraviolet rays carry a higher wavelength than that of microwaves. Both of these rays are typically not visible to the human eye.
There is also a color spectrum included in the rays emitted by the sun. It consists of the visible colors of the rainbow that humans can see with their naked eyes. Plants absorb these rays, too, but not all of the rays carrying all the colors we see are used up by plants. They only absorb two colors ranges – the yellowish to the red range and the bluish tinge.
Using grow lights as a substitute to natural light means that these artificial lights should come as close as possible to the wavelengths naturally emitted by the sun. This is so that the plants can absorb adequate amounts of light that they will need to generate their food through photosynthesis and chlorophyll absorption. When plants get the proper wavelengths they need, food production increases and they will grow healthier in time.
Full Spectrum Grow Lights
Now, there are also lights that can be classified as full spectrum glow lights. These fixtures offer wavelengths that are within the spectral range of light used by plants to carry out photosynthesis. The spectral range is called Photosynthetically Active Radiation (PAR), and its value falls within 400 to 900 nanometers. There are several ways on how PAR is measured, and new ones keep on being discovered (7).
Full Spectrum Grow Lights are those lamps that emit a continuously broad range of light wavelengths across the entire PAR range. Such lights are able to fill up the entire growing area as a primary source of sunlight-substitute light. These fixtures can sufficiently sustain a plant throughout all propagation stages, from initial growth to the fruiting stage and beyond.
A wide range of grow lights can fall under the full spectrum category. This includes LED lights, fluorescents, and metal halides.
The latest models of LED grow lights have shifted their focus from color temperature ranges to providing the widest possible range they can offer. That’s why models that emit full spectrum wavelengths are now currently created and marketed. Old models of LED lights have pinkish or purplish hues due to their focus on the warmth or coolness of the lights. But now, they’ve been using the “white chip” technology to produce LED lamps that give off white color and emit a full spectrum range. White chips are made by coating the diode with phosphor.
Fluorescent light makers also offer full spectrum models of their fixtures. Standard T2 lights and compact fluorescent lamps all carry a variety of full spectrum lights with a color temperature of 5,000K. If you’re looking for a grow light that’s considerably cheaper than LED lights, you can go for this option.
A type of High-Intensity Discharge (HID) light called Metal Halides is also considered a full spectrum grow light. Lots of experienced farmers have used these lamps to cultivate a wide variety of crops.
LED Grow Light Strips
Have you ever seen strips of tiny alternating red and blue lights inside an indoor plant growing area? Then you’ve already seen what grow light strips look like. These lights are made up of tiny LED lamps that are welded together to form long strips, then clustered overhead a group of plants to serve as s grow light. Some indoor farmers prefer to use these than the conventional grow lights because they’re easy to use, effective, and aesthetically pleasing to the eyes.
How are these tiny yet powerful grow lights formed? Manufacturers weld small LED bulbs (usually red and blue in color) onto a flexible circuit board. Both the bulbs and the circuit board are then wrapped in flexible plastic to make it more insulated and waterproof. Then, the completed light strip is connected to a power source (usually USB cables) to emit the light.
Earlier processes of creating LED grow light strips consists of welding the bulbs to a flexible copper wire, then attaching the wire to PVC pipes. But this has since been replaced with the flexible circuit boards as the base instead of the copper wires.
Indoor plant farmers prefer to use these strips for a variety of reasons.
The light strips are soft and flexible. They can also be cut into the desired length that matches that of your indoor growing area.
The lights are waterproof and have good insulation, thanks to the plastic that wraps around the strip securely. Since LED lights are energy-efficient, it is less prone to heating, and therefore won’t melt the plastics easily.
LED grow light strips are also weather-resistant and have the same lifespan of about 50,000 hours as the typical LED fixtures. These tiny lamps also have the ability to offer a full spectrum of wavelengths to suit all of your plant’s propagation needs.
The light strips can be arranged into rows on top of the plants in a grow light system. The finished arrangement looks great and is as good as the benefits it can give to the plants.
Plants need sunlight to grow and thrive. But sunlight isn’t always available all year round. That’s why grow lights are conceptualized and created.
Grow light systems are great for the continuous growth of home plants, vegetables, fruit-bearing plants, flower crops, and herbs during the winter seasons. Grow lights enable these plants to grow and bear fruit even when they are indoors and are not experiencing the natural rays of the sun.
Several types of grow lights are available for you to choose from depending on your plant growing needs. These include incandescent lights, fluorescent lights, high-intensity discharge lights, light emitting diodes, and sulfur plasma lamps. Each of them has its own wavelength ranges and are suited for the several stages of plant propagation.
Plants need certain wavelengths emitted by the sun and by artificial grow lights so that they can start the process of photosynthesis. These wavelengths vary greatly and can fall anywhere within the color spectrum of light. Warm grow lights are those that fall at the lower end of the spectrum and are perfect for blooming and fruiting stages of plant propagation. Cool grow lights are the exact opposite, lights that emit wavelengths at the higher spectral end and are used to grow new seedlings until they vegetate well.
Grow lights can easily be installed in your home indoor garden. But before that, you need to factor in your plant variety, how many plants you have, its spacing and arrangement, and the type of grow light you intend to use. This is because grow lights must be suspended at a height that’s not too near the foliage because of the risk for plant burns and heat overkill.
Keep in mind that as your plants grow, you might need to raise the height of your grow lights further away from them. Bigger plants may not need a lot of light and heat as much as the seedlings and smaller plants do. And as the height of the lamps increase, the light dispersed to the plants decreases – this principle is known as the Inverse Square Law.
Other types of grow lights that are popular nowadays include LED grow light strips and full-spectrum lamps. They are both great for all-around plant propagation and are suited for several plant varieties.
To conclude, creating grow lights in your home garden is indeed doable. With the right research, adequate lamps, and lots of dedication and patience, you can grow your crops all year round with the help of your trusty home grow lights system.