You can not use any LED light to grow plants. LEDs have many different industrial applications, so they’re not all suited for plant growing.
There are two main type of grow lights used to grow plants – I list the differences here in my HPS vs LED grow light guide.
To grow plants successfully using LEDs, you need LED grow lights that emit a specific color spectrum and a sufficient intensity level. LED grow lights capable of growing plants should emit pink/purple or white colored light.
Better quality LEDs for plant growth utilize a full white spectrum that consists of blue, yellow, orange, green and red wavelengths. The required light intensity will vary from application to application.
LED lights for fruit, vegetable, and cannabis plants should emit a minimum of 306 micromoles of light (PPFD) for an 18 hour exposure period, or 617 micromoles for a 12 hour exposure period.
The most modern LED grow lights are COB LED grow lights and Quantum Board LED grow lights. You can click those links to read the articles I wrote about them, and perhaps pick one that suits you best.
You need to ensure your plants are receiving light from a full spectrum LED light and that only comes from the best LED grow lights.
Detailed Plant LED light spectrum requirements:
Plant’s lifecycle includes a vital process called photosynthesis which makes it possible to get the required amount of sugars by processing light energy absorbed by the leaf.
This glucose sugars further pass through several phases, and plants experience growth through this entire process. The subject in the question is LED Lights which are nowadays a must have prop in an indoor garden.
Notably, in the weed grow space LED lights play a vital role behind well-developed plants.
Weed plants have a bit different nature and requirements regarding sustainability and hence need a properly lighted environment for the better life.
Not All LED Grow Lights Are Created Equal:
Normal LED lights comprise of just a few color wavelengths like white and yellow, but cannabis plants need light as close to natural sunlight as possible.
Sunlight comprises of several light wavelengths and different range of colors like orange, green, violet, purple, red and so on.
Similarly, weed plants need almost all the bands of colors for better growth.
The LED grow light market is a most competitive market where you’ll get several brands offering different light for different purposes.
Inexpensive LED grow lights can be a real problem. The cheapest ones often don’t emit a full spectrum of light needed to grow a plant.
With that said, you can still grow a plant with a quality LED grow light. There are inexpensive ones strong enough to grow an individual house flower in a small space. That’s great if that’s what you’re looking for – in that case you should check out my experience with the Sansi 36w LED bulb.
But growing bigger plants like fruit, vegetables, or cannabis require LED lights that emit stronger light. If you’re in this camp I highly suggest you check out my homepage, where I’ve posted the results of several hours of research into the best LED grow lights for this purpose.
How do LEDs for horticulture applications work?
It starts with science. The whole purpose of horticultural lighting systems has been to enable plant growth in indoor environments using artificial light. LED light manufacturers perform experiments and read scientific literature about the specific light color wavelengths and how plants respond to them.
While a perfect combination of light color wavelengths isn’t settled science, manufacturers have a good idea of what LED light wavelength mixtures bring results.
A recent study discussed the importance of several wavelength colors – Red and Far Red, Blue and Ultraviolet, and Green. Each color has its own unique effects on plant growth, and manufacturers of LEDs for horticulture purposes understand and incorporate these colors into their LEDs.
Most brands manipulate sunlight spectrum in an LED Panel to create similar real light effects.
A light which has the majority of blue spectrum suits plants passing through the vegetation phase. During this phase your cannabis plants need light comprising blue spectrum. This sort of light usually creates the purple effect in the grow space by delivering a dominant blue spectrum to the plants.
On the other hand, red colored spectrum is vital for plants growing through a flowering phase. However it’s good to use light with the majority of the blue band in its spectrum so that plants can produce resinous and heavyweight flowers at the time of harvest.
There are various studies available on the internet that explain how these two bands (Red and Blue) play an essential role in indoor plant’s growth and health.
Here’s a quick and easy to understand visual representation of light bands. This picture also includes the importance of each group in plant’s life cycle.
Have a look!
The PAR spectrum, PPFD, and DLI:
You’ll be glad to know that I spent a ton of time researching different lights for my readers. Most people shopping for grow lights get overwhelmed by all the different factors to consider, and simply buy the cheapest light around. That’s a massive mistake. If there’s one piece of indoor gardening equipment you don’t want to skimp on, it’s your grow lights.
Check out my article “Grow light PAR, PPF, and PPFD values decoded,” where I break down the science of light specifically for cannabis growers. You’ll be amazed of the difference in plant yields from a quality grow light and a low quality one.
What are some LED lights capable of growing plants?
On my homepage I’ve compiled a list of top notch led grow lights at every budget level. But for the sake of convenience I’ll list a couple very capable LED grow lights for growing plants here:
Small Space / Low Cost:
Mars Hydro TS 600:
A modern white spectrum LED grow light capable of growing plants in a small space, without breaking your wallet. This grow light meets the criteria I named above – light spectrum and intensity.
Larger Space / Higher Power:
Phlizon CREE COB LED grow light:
This is the Phlizon CREE COB series grow light, made with top shelf CREE brand COB LEDs. This light is capable of covering a larger area and emitting higher intensity if you want to ensure a higher yield out of your cannabis, fruit or vegetable plant.
Growers really love this light and it’s why I recommend it here at 420expertguide as one of the strongest COB LED grow lights you can buy.
Are HPS or LED lights better for growing plants?
HPS or high pressure sodium lights are the type of light used before LEDs went mainstream. There are a few use cases where I still think you can grow plants using an HPS light compared to an LED light.
The first case is if you’re growing in an open space that has decent air circulation. The open space and air circulation are critical to dealing with the amount of heat generated by HPS lights.
The second use case for HPS lights is if you have a large grow tent (5×5 foot or larger) that’s well ventilated. Even in this second scenario the cost of using HPS lights may come close to using LED lights.
LED lights for plant growth have several benefits, although they’re still priced slightly higher, the pricing has improved in recent years as competition has grown.
A recent study summarizes pretty well the benefits of using LED lights to grow plants:
LEDs can be optimized to specific production conditions by controlling periodicity, quantity, and spectrum of the light provided (Pinho et al., 2007). LEDs allow high-density production systems to have a focused spectral quality that can maximize radiation transfer to plants (Nelson and Bugbee, 2014). Their low heat emission allows them to be placed in the plant canopy for maximum cannabinoid yields.
To summarize, LEDs feature better light spectrum, better energy efficiency, and at the high end of the LED light market, the coverage area is better than HPS lights.
My video explaining how much light intensity you need to grow plants:
Can you use any LED light to grow plants?
No. LEDs have many different applications, not all LED lights are suited for growing plants.
What’s the difference between HPS and LED grow lights?
LED is a newer technology that has advanced to a point of being more efficient and more customizable for plant growth.
What color LED is best for plant growth?
White spectrum LED lights were proven best for plant growth in several university studies. Pink / purple colored grow lights still work, but slightly less.