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Can a regular light bulb help plants grow? Yes, as long as it delivers enough PAR light to your plants. LED lights are great because they’re energy-efficient, emit little heat, and last for years. However, it’s probably best to get a horticultural light for plants with high light requirements.
Regular LED Lights For Plants — A Bright Idea?
If an indoor plant needs more light than any of your windows provide, you’ll have to get a grow light. But at what cost? Many don’t run cheap.
Can you use regular LED lights for grow lights? Yes, but not just any will do. In this article, I’ll explain the benefits of LEDs, the importance of PAR and PPFD, several lighting terms, and some grow light misconceptions.
How LED Lights Outshine Others
Out of incandescent, fluorescent, and LED lights, LED lights shine for their low heat emission, energy efficiency, and long-term cost-effectiveness.
A 16.5-watt LED bulb is as bright as a 20-watt CFL or 75-watt incandescent bulb, all-the-while being cool to the touch.
Incandescent bulbs run so hot that they should be at least 24 inches (61 centimeters) above your plants. Fluorescent bulbs can safely be 12 inches (30.48 centimeters) away, and LED bulbs can be six inches (15.24 centimeters) away.
If you’ve considered keeping your plants warm with a regular lightbulb, it would be better to use one of these heat lamps.
Though they’re the most expensive up front, LED light bulbs last 2 to 4 times longer than CFL bulbs and 25 to 35 times longer than incandescent bulbs. And unlike CFL bulbs, they don’t contain mercury.
Can Any LED Light Be Used As A Grow Light?
Despite the above benefits, not just any LED light can be used as a grow light.
When researching light bulbs, you may encounter terms such as:
- Color temperature
- Foot candles
Out of these, only the last two matter for gardening. But before I explain them, I’ll tell you why the first five don’t.
Color Is Extremely Important – Color Temperature Isn’t
Though plants use all colors of light (including green), they especially benefit from red and blue light. These colors of light help not only with photosynthesis but also with growing specific parts of a plant. Red light helps plants grow flowers, and blue light helps them grow foliage.
On other blogs, you may have encountered misinformation on color temperature. Many people assume that just because a light looks like a color, it will help plants do things associated with that color. But this is not true.
Color temperature measures how a light looks, not it’s actual color spectrum distribution. Two light sources that look identical in color may emit colors in very different amounts.
The 2Hr Aquarist compares a 6,500 K LED light, which resembles the color of sunlight, to actual sunlight with these wavelength distribution charts:
- the color distribution of sunlight:
- the color distribution of a 6,500 k led light bulb:
As you can see, though both light sources are high in blue light, the sun emits much higher amounts of other colors compared to the light bulb.
Lumens Are For Humans – So Are Lux And Foot Candles
Lumens measure the apparent brightness of a light.
Humans perceive the middle of the color spectrum — the green portion — as much brighter than the blues and reds on either side. As a result, a good horticultural light may look relatively dim to people. Purplish grow lights are a common example:
LUX and foot candles are also useless for gardening because they measure lumens per square area.
Why Not Watts?
Watts are even less useful than lumens for measuring light intensity. Though they measure electricity, watts used to correlate strongly with the brightness of light bulbs. This is no longer true now that more energy-efficient bulbs exist.
Plants Prefer PPFD
PPFD (Photosynthetic Photon Flux Density) measures how much PAR (Photosynthetic Active Radiation) reaches your plants per second. This metric is the most useful for gardeners because it measures light quality and intensity from a plant’s perspective.
PAR refers to the region of the light spectrum (400 to 700 nm) useful for photosynthesis. Contrary to what others may mistakenly tell you, PAR does not measure light intensity, nor is it even a measuring unit. It’s simply the wavelengths of light plants can use.
Unfortunately, you’re unlikely to find references to PPFD on regular light bulb packaging. You can determine it on your own, but only if you buy equipment such as a quantum sensor . If you used a quantum sensor, you’d place it right at your plant’s level to see how much high-quality light was reaching its uppermost leaves.
Seeing as you’re trying to save money, there are three cheaper routes you can take:
Find Reviews By Other People
You can find reviews of regular LED lights from people who have the right equipment. Here’s one by LEDTonic:
You can also find reviews by people who tested regular LED lights through trial and error.
Take A Leap Of Faith
You could just use a regular LED light as a grow light and see what happens. You’d probably have more success with plants that have low light requirements, such as many grown in indoor herb gardens. (For more indoor garden ideas, read this listicle by Nadya.)
Get An Affordable Grow Light
For plants that need more light, I’d recommend getting a real grow light. It doesn’t have to be expensive, especially if you get a single bulb like this full-spectrum COB LED Light .
Do LED lights help plants grow?
Because they use less electricity and emit less heat, LED lights are much better for indoor gardening than fluorescent or incandescent lights. You can save money by using non-horticultural LED lights as grow lights, but only if they emit enough of the right wavelengths
How close should LED grow lights be to plants?
Because LED lights emit little heat, you can safely place them 6 inches above your plants. This close proximity allows the most light to reach your plants. In comparison, fluorescent bulbs should be at least 12 inches away, and incandescent bulbs should be at least 24 inches away.
Hope You Found This Article Enlightening!
Can you use regular LED lights for grow lights? You can, as long as they deliver enough of the right colors to your plants. As a recap:
- Red light helps with flowering.
- Blue light stimulates foliage growth.
- PAR is better than color temperature for determining a light’s color quality
- PPFD measures the quality and intensity of light from a plant’s perspective
- A good grow light may look dim because certain colors look brighter to people
To avoid doing research, you can simply buy this full-spectrum COB LED Light .
If you have any questions, please let me know in the comments!
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Last update on 2020-10-29 at 09:19 / Affiliate links / Images from Amazon Product Advertising API