LED Grow Lights For Indoor Plants

LED grow lights are made up of light-emitting diodes, and are advantageous over other methods of plant lights because they consume much less electricity and the typical LED has a life span of 50,000 hours (if on a 12 hour timer, 11 years).

If you use an alternative energy source in your home (e.g. solar or wind power) electric power consumption is always a concern. If you’re supplementing indoor plant growth (especially during the winter) an LED grow light might be helpful.

Not all LED grow lights are the same however:

While the LED technology and its implementation to “grow lights” is still relatively new, there has been some research to indicate that not all LED grow lights are the same with regards to successful growing of indoor plants.

LED grow light models can now be customized for specific wavelengths of light.

Instead of just one wavelength (color), studies have revealed that combinations of green, red, far-red and blue light shave beneficial effects on plant growth.

While it is possible to grow plants under only red LED light, the plants will generally display unhealthy growth.

Studies have shown that many plants will grow normally under a combination of both red and blue light.

Further studies have shown plants will grow even better under a combination of red, blue and green wavelengths.

From Wikipedia,

In tests conducted by Philips Lighting on LED grow lights to find an optimal light recipe for growing various vegetables in greenhouses, they found that the following aspects of light affects both plant growth and plant development:

-light intensity
-total light over time
-light at which moment of the day
-light/dark period per day
-light quality (spectrum)
-light direction and light distribution over the plants.

However it’s noted that in tests between tomatoes, mini cucumbers and bell peppers, the optimal light recipe was not the same for all plants, and varied depending on both the crop and the region, so optimizing LED lighting in greenhouses is based on some trial and error.

The diodes used in initial LED grow light designs were usually 1/3 watt to 1 watt in power. However, higher wattage diodes such as 3 watt and 5 watt diodes are now commonly used in LED grow lights.

LED grow lights should be kept at least 12 inches away from plants to prevent leaf burn.

A popular “Best seller” LED plant grow light:
45W LED Plant Grow Light with Red Blue Spectrum

Here’s a powerful unit, “full spectrum”,
300w 12-band LED Grow Light

There are LOTS of LED grow lights on the market today in a wide variety of sizes, shapes, even strip lights. Some are designed to be very powerful while others will light up a small desk plant. If you’re interested, you can search for them here…

Do any of you use plant grow lights?
What has been your experience?


  1. My Fiancee and I made a foray into apartment level aquaponics with the the Back to the roots water garden Fish tank.
    Back to the Roots Water Garden Fish Tank

    and we used a neat and small grow lamp. We did not see much growth at first because we get poor lighting in our old apartment. With the light that all changed.
    LED Plant Grow Light 7W Desk Grow Lamp

    We were doing gangbusters with wheat grass and a couple different herbs, but it was difficult to get the right balance to keep the tank clean and the water creatures healthy. “Beta fish,ghost shrimp, zebra snail”. The Idea was to have the right balance of bottom feeders and the fish with the plants to support growth and water filtration. in the end we lost the fish and retired the tank until we had more time to put into it. Aquaponics has always interested me and this was a neat inexpensive early foray for us to learn from.

  2. I use grow lights as I start a lot of seeds indoors and we have a short growing season. I bought 3 long tube lights at a garage sale and they work great. I didn’t know there was so much science behind them.

  3. I use the Ottlight, so it’s not LED. I’ll keep using them until they all burn out, which should be about fifty years from now. :) I bought them over ten years ago and the first went out this winter.

    1. We use Ottlights too. They are great for our seedlings and keep our clementine tree happy during the winter.

  4. Only experience I have had with “grow lights” was back in the 60-70s in California, had one stuffed into a closet with a few plants……. No further comment on that “experiment”.. LOL

    I happen to know a few ‘buddies’ that are very much into grow lights that live now in Colorado, from what they talk about they use lighting very similar to what you described here. And their businesses are thriving like crazy.

    I’m thinking once retirement hits I’ll be the time to get into more home starts for the Garden, something about time right now, unfortunately. But these look like a good idea.

    Thanks for the info Ken.


  5. Ive been looking into grow lights for the greenhouse, extend the light hours on starts, in combo with a heat mat you can really speed up germination and growth in your starts, just need to be aware that hardening off your starts is more important when using alternate light or heat sources

  6. No puns intended but I have to use certain words to try to be coherent in this post-
    In my work I am exposed to may different types of LEDs that are used in our products. We concentrate on wavelength and intensity. I have been thinking about grow lights in my basement since the growing season is short where I live (foot of snow on the ground now with a possible 4-8 more inches on the way Friday/Saturday). So this article is very interesting, thanks.

    The Red, Green, Blue (RGB) mentioned as the important wavelengths:
    Red 630 – 700 nm (nanometers)
    Green 490 – 560 nm
    Blue 450 -490 nm
    How this matters to the plants I have no idea, but will need to figure that out. In my work we worry about 1/2 nanometer wavelength shifts, not so much with plants I’m sure. The LED distant matters due to the cone of emission and intensity of the light. Common sense says, farther away is less intensity and wider cone of emission, there is a distance point of diminishing returns.

    1. Blue light promotes foliage growth (perfect for starting plants and your lettuces and other leafy veggies…) (“Temperature” of 6500 Kelvin…. Look for “6500” on a blue light.. I use T5’s not LED’s, so I don’t know if that relates)

      Red lights are important for flowering (indoor tomato’s, Cucs and peppers)… Reds are in the 30OO Kelvin temperature range (I don’t have any of those as I’m using mine to start transplants, so others may have better information)

      Not sure where (or how plants use) green comes into play… Always something to learn!


  7. One of the books I have on growing NRP’s experiment also talks about different light wave lengths. I didn’t realize that light was so important. No wonder I can’t grow anything except mold and mildew.

  8. Here in Or. grow lights are very common mostly used for growing Pot. Which preppers should think about growing lots of medical uses from cancer to muscle pain, their are strains with a high cbd content that are made into lotions. At are farmers market a vender sell honey with a high cbd content. Just something to think about.

  9. This past winter I used an LED grow light for 2 plants I keep outside normally. The cactus did not seem to mind it, but the leafy plant hated it. The leaves contorted, and turned an odd color of reddish green hue.
    Before LED I would use a purplish pink florescent grow light, and the plant would flower in the winter.
    As Ken’s artical points out the is some trial and error to work through.

    Have a great day!

  10. I would like to point out that almost every LED light is run by a constant current controller (a small box of electronics) this controller only has a lifespan of 1 to 5 years depending on quality of components and environmental factors.

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