A regular light bulb can help plants grow, but the results might not be as satisfactory as those provided by grow light bulbs. That’s because grow light bulbs emit a full spectrum of light that plants need to grow and thrive, something which regular light bulbs fail to do.
However, that doesn’t mean that you should immediately replace all the regular light bulbs in your indoor garden. Doing so won’t be necessary, especially if you’re just starting out with a few plants, as ordinary bulbs are more than enough for a beginner stage garden.
Once your seeds have sprouted and you see they’re entering the budding stage, it’s time to replace regular bulbs with grow lights. Plants in the budding, flowering, and ripening stages need greater intensity light than what regular light bulbs can offer. As a result, they could do with grow light bulbs.
What Types of Bulbs Can be used to Grow Plants Indoors?
Multiple types of bulbs can be used to grow plants indoors. They include LED bulbs, incandescent bulbs, fluorescent bulbs, halogen bulbs, and high intensity discharge bulbs. All of them offer different intensity light, so you’d do well to research how much light your plants need before selecting one of these.
Here are the major types of bulbs that can be used to grow plants indoors:
LED Bulbs
The best LED grow light bulbs are incredibly long-lasting. They tend to last for as much as 50,000 hours and run at cooler temperatures. There’s little to no danger of them burning tender plants, regardless of the distance between the plant and the LED light bulb.
Another excellent advantage of using LED grow bulbs is the full spectrum of light they provide. When you go for LED, you don’t have to switch lights as your plants go from one growth cycle to the other. The LED light bulbs will stay with your plants from sprouting to ripening.
What’s more, LED lights can also easily go into narrow spaces and consume little electricity. They are also way more efficient that other grow lights, which means lower electricity bills. Their only drawback is LEDs greater purchase cost, though they offset it with their negligible running costs.
Pros
- Run at relatively cooler temperatures
- Consume less electricity than other grow lights
- Produce much greater light intensity
Cons
- Cost more upfront
Fluorescent Light Bulbs
Fluorescent light bulbs cost less than their LED counterparts, though their light intensity cannot compete with that of LEDs. Their relatively weak light intensity serves as a blessing in disguise, as it makes fluorescent light helpful for plants in their germination and vegetative growth stage.
You have two options if you decide to go for fluorescent light bulbs. Fluorescent tubes are compact than LEDs and are more budget friendly, too. This allows them to get into spaces where even an LED can’t go, making fluorescent tubes a must-have if you’re growing plants in a small/narrow space.
Then there are the compact fluorescent light (CFL) bulbs. They are known for their lower power consumption. These bulbs are more conducive for small plants, seedlings, and clones. Among the various types of CFL bulbs, ‘T5’ bulbs are the best for growing plants because of their excellent light output.
Pros
- Produce less heat
- Cost less upfront than LEDs
- CFL offer a wider light spectrum
Cons
- Won’t last as long as LEDs
High Intensity Discharge Bulbs
High Intensity Discharge (HID) bulbs are known for their massive light intensity. They emit extremely bright light by burning a rare gas inside the glass. Environmentalists caution that this doesn’t make HID bulbs very safe for the environment. But it does allow them to illuminate large spaces with ease.
Similar to their fluorescent counterparts, HID bulbs also come in two types. The first are the metal-halide (MH) bulbs. MH bulbs give off blue-colored light, which belongs to the cooler light spectrum and is highly beneficial for plants that are in their vegetative growth stage.
The second type of HID bulbs are known as High Pressure Sodium (HPS). HPS bulbs emit light in the red-to-orange color spectrum. This spectrum is known as warm. It is beneficial for tomatoes, cucumbers, peppers and vegetables in their flowering growth stage.
Pros
- Are extremely efficient
- MH lighting promotes leafy growth
- HPS lighting helps plant produce buds and flowers
Cons
- Consume lots of electricity
Incandescent Light Bulbs
Incandescent light bulbs are the cheapest option as far as grow lights are concerned. They are also the easiest to find. These lights produce light in the red side of the spectrum, but we’re yet to find any expert recommending incandescent light bulbs for growing plants. Here’s why.
First of all, these light bulbs get extremely hot within minutes of their operation, thereby posing a safety hazard if a) you leave them on for a long time or b) you’re growing plants in a small space. Manufacturers recommend ensuring a distance of at least 2-feet between these lights and your plants.
Secondly, and this drawback stems from the first, incandescent light bulbs have an ultra-short life span. While an LED light bulb can last for 20,000 hours on average, you’d be lucky to stumble upon incandescent light going strong after 1,000 hours. That’s why you shouldn’t use them for growing plants.
Pros
- Cost less upfront
- Help plants in their flowering and budding phase
Cons
- Last for less than 1000 hours on average
- Produce excessive heat
- Poor energy efficiency
Halogen Bulbs
Halogen bulbs are one type of incandescent light. They consist of a tungsten filament enveloped by a compact glass and surrounded by an inert gas. When an electric current is introduced to the mixture, a chemical reaction ensues, causing the tungsten to light up.
The mixture’s role doesn’t end once the tungsten has lightened up. It’s also responsible for ensuring that halogen bulbs operate at higher temperatures, usually 2,700 to 3,500K. Though the higher running temperatures have a downside: they reduce the shelf life of halogen bulbs to 3,600 hours, at most.
Despite all these features, halogen bulbs shouldn’t be used as grow lights. Mainly because they emit UV and IR rays that could end up damaging your plants. But also because halogen lamps, like their incandescent counterparts, tend to get very hot.
Pros
- Are super-bright
- Lasts 3x as long as incandescent light bulbs
Cons
- Tend to get extremely hot during operation
- Not as efficient or as compact as LEDs
- Are too hot to the touch during operation
Can Regular Bulbs Help Plants Grow?
Regular bulbs can help plants grow very cheaply but very inefficiently too. That’s because these bulbs, which are mostly incandescent, use more electricity than LEDs while giving the same output. In simple words, they lose a lot of electricity in the form of heat.
However, if you’re a first-time grower still learning the ropes of indoor farming, we suggest you stick with your regular bulbs for the time being. They don’t cost much, use less power and last longer than both incandescent as well as halogen bulbs, thereby letting you save money.
While using regular bulbs, make sure they are placed at an adequate distance from the plants. You can use the back-of-the-hand test to ensure that. Place the back of your hand at a reasonable distance from the plant. If your hand gets too hot, the distance is unsafe for plants. Move back.
Once you’ve learned the ropes of indoor farming – and your seeds start showing signs of life, we suggest you replace regular bulbs with LED grow light bulbs. Sure, the endeavor will cost you a few bucks, but it will end up nourishing your plants.
Can LED Light Grow Plants?
LED lights are your best bet for growing plants for four specific reasons, the first of which has to do with their low electricity consumption. The United States Energy Department has estimated that compared with their incandescent counterparts, LED lights use 75% less energy despite lasting 25 times longer.
Secondly, LED lights emit very little heat, thereby posing little risk to plants placed nearby. You can verify this from the fact that while CFLs release 80% of their energy as heat and incandescent bulbs give off 90% of their energy as heat, LEDs emit less than 5% of their energy as heat.
Thirdly, LED lights are much more concentrated than other types of lighting we saw above. Other types of lighting emit light in all directions, forcing you to use reflectors to reflect the light onto your plants. LEDs don’t do that, which helps you focus the LED bulb directly on your plants.
Lastly, LED lights have meager running costs. An estimate by the US Energy Department proved that by comparing LEDs, incandescent, and CFL lights for 2 hours a day for 365 days. Assuming a unit of electricity costs 11c/kWh, LEDs annual energy cost ($1) was the lowest of all sources.
Frequently Asked Questions
Can plants grow in artificial light?
Plants can successfully grow in artificial light, as long it has most of the wavelengths of natural sunlight. That’s because it’s its equal distribution among different wavelengths that makes sunlight your best bet for plant growing and blooming.
Plants need blue wavelength in the early stages of their growth cycle (sprouting and germination). They then need red wavelength for ripening and fruiting. Sunlight contains both these wavelengths in perfect balance. If your artificial light has the same balance, then it too will help plants grow.
How to grow tomatoes indoor with lights?
Use these step-by-step approach to grow tomatoes indoor with lights:
- Choose indeterminate (vining) tomato varieties. With proper care, they’ll easily grow and produce fruit.
- Sow the tomato seeds at least 2 months before you plan to harvest your tomatoes. Plant them in a container full of fresh water after poking a ¼’’ deep hole in the container. With your fingers, sow at least 3 seeds per hole.
- Once you’ve sowed them into the container, cover the seeds with a sheet of plastic wrap or a lid. Then move the container to a lukewarm location. Once or twice a day, remove the lid and water your tomato seeds.
- After the seeds start showing signs of sprouting, they’ll need at least eight hours of light daily. So make sure the plants receive as much light by removing their lid and placing them in front of the south-facing window.
- Once your seedlings sprout into one or two sets of leaves, transplant them into a seven to 10 gallon container. Take extra care when removing the seedlings from their cells, or else you might end up breaking their roots. Warm them after transplantation.
- Once you’ve transplanted them, tomato plants will need 12 to 16 hours of light every day. If you’re using artificial lights, use a timer to ensure the lights turn off to give your plants the time to rest in darkness.
- Keep on fertilizing your tomato plants during all this time. We recommend using a phosphorus-rich fertilizer.
- Use a cage or stake to ‘train’ your tomato plants to grow up. If you intend to use a cage, place it over the plant while it’s still small and bind it around the container. This will allow the growing suckers to climb the cage’s walls on their own.
- Assist birds and bees in the pollination process by directing a standing fan towards your tomato plants. Shake the plant’s main stem gently with your finger. Then pollinate it with a cotton swab or paintbrush.
- After 60 to 80 days of sowing indeterminate tomato seeds, the plants will be ready to bear fruit. You’d know when the plant is ready for harvest when the tomatoes turn a vibrant red or pink color.
- Once you have made sure that the plant is ready to harvest, grasp it by the step and twist it until the tomato snaps off.