Ultimate Guide To Full Spectrum LED Grow Lights for Indoor Plants

How can you select the best full spectrum LED grow lights for indoor plants? Well, we guarantee it won’t be easier, but once done, it becomes possible to grow any plant indoors throughout the year. 

Generally, manufacturers design these lights to mimic natural sunlight by providing specific light spectrums to support growth phases (vegetative, flowering, and fruiting). 

Besides converting almost 90% of the incoming energy into useful light, these lights also have adjustable settings to help you control light intensity and wavelength. 

Today’s article focuses on everything full spectrum grow lights for indoor plants to help you make a wise gardening decision. Let’s get rolling!

The Meaning of Full Spectrum

Full spectrum involves lights containing all visible spectrum wavelengths (red to violet) and infrared and ultraviolet lights. 

Therefore, it is the closest thing to natural light since it has all the wavelengths and colors we find in natural sunlight. 

Manufacturers are now employing the full-spectrum concept to design artificial lights using LEDs. 

Full-spectrum LED lights bring several benefits over high-pressure sodium and metal halides, including converting over 90% of energy into useful light. 

Moreover, these lights are highly versatile and come with adjustable settings to help you manipulate color and wavelength to meet the plant’s requirements. 

Blue/Red Full Spectrum LED Grow Lights

Colorful LED lamps

(Colorful LED lamps)

Blue and red light wavelengths are the main light spectrum in LED grow light we use for plant growth.

 For instance, the blue light at 400-500 nm is responsible for root development, vegetative growth, and general plant compactness. 

It accomplishes this by regulating critical processes like stomatal opening, chlorophyll production, and photosynthesis. 

Conversely, 600-700 nm red light supports plants’ fruiting and flowering phases. 

Therefore, a full light spectrum combines red and blue to produce a tailored spectrum supporting the growth cycle. 

And in some cases, the full spectrum has supplemental spectrums like white, UV, and infrared. 

A combination of red and blue LED light produces the most energy-efficient solutions, making metal halides and high-pressure sodium appear like a joke. 

As per research, these solution converts more than 90% of the supplied energy into useful light energy. 

Moreover, these lights have a customizable option that allows gardeners to adjust the light brightness, wavelength, and intensity to meet the plant’s specific needs. 

Is Full Spectrum Grow Light Necessary?

Vegetable growing under LED light

(Vegetable growing under LED light)

Whether you need a full spectrum or grow light depends on the following factors.

Natural Light Availability

We understand that plants grow and make food thanks to natural light from the sun. 

But in the absence of natural light, in the case of indoor gardening, we should improvise and create conditions similar to natural light. 

The only option closest to natural light is a full spectrum grow light, which supplies all the light wavelengths supporting growth. 

Growth Phases and Plant Species

Different plants and growth phases require specific light to grow optimally.

 For example, most leafy herbs require blue and red wavelengths to achieve maximum growth.

 However, other plants, especially those that produce fruits, will require light that mimics the properties of natural light. 

Therefore, if you’re unsure exactly what your plant requires, we recommend employing full-spectrum light to cover all growth phases. 

Low-light Environments/Indoor Gardening

Growing vegetables using LEDs

(Growing vegetables using LEDs)

Full spectrum lights are the only solution if plants grow in a low-light or indoor gardening environment. 

Generally, they can comfortably replace natural light by providing the relevant wavelength to support photosynthesis and overall growth. 

Supplemental Lighting 

Even if natural light is available, supplying extra light to your plants through full spectrum light guarantees optimum growth. 

This happens especially during winter to extend the daylight hours and improve productivity. 

Specific Goals

The good thing about full spectrum lights is the emission of specific wavelengths that support unique growth phases. 

Usually, the light has all the wavelengths and can support all phases, including vegetative, flowering, and fruiting. 

Therefore, if you intend to have more fruits, you have no option but to use full spectrum lights. 

Tips for Growing Indoor Plants Under Full Spectrum LED Lights

A woman watering indoor plants

(A woman watering indoor plants)

You’ll get the desired result if you follow the following tips while growing indoor plants under full-spectrum light: 

Select an appropriate spectrum: Begin by selecting high-quality LEDs that offer a balanced full-spectrum light

Therefore, choose a solution that provides all light wavelengths, including red, green, white, and blue lights. 

Also, consider the coverage area and light wattage to ensure they meet your plant requirements. 

Know your plant light requirement: Since different plants have unique light requirements, research the photoperiod, intensity, and spectrum that fits your plant. 

You might have to supply red light for flowering and blue light for growth. 

Use an appropriate light distance: Placing the light too close might cause burning due to heat. Similarly, having the light far could provide insufficient light, thus affecting optimum growth. 

Therefore, an appropriate height of about 12-24 inches above the plants could offer the best results. 

However, you should monitor your plant’s response to light and adjust it appropriately. 

Keep a good lighting schedule: Establish a lighting pattern similar to natural light. Therefore, about 12-16 hours of light exposure to your plant during the day is enough.

 Plants, too, require the night off to rest. 

Ensure proper watering, temperature, and humidity: Although grow LED produces less heat than metal halides and high-pressure sodium options, you still need to monitor the humidity and temperature in your garden.

 And if the temperature is high, provide proper air circulation and, where possible, heat management systems. 

Besides light, plants also require sufficient water to achieve optimum growth. Therefore, ensure you water your plants regularly, considering the growth phase. 


How long should you leave your grow light on daily?

The period you leave your grow lights on depends mainly on the plant’s growth phase and specific requirements. 

Most plants require at least 12-16 hours and 10-12 hours during vegetative and flowering stages. 

To be on the safe side, research the particular plant you have and restrict yourself to the recommended hours.

 But remember to leave your plant for a few hours at night without light for resting. 

Full Spectrum LED Grow Lights for Indoor Plants: Can you use regular LEDs for plant growth?

First, you must understand that for plants to achieve optimum growth, you should supply the right light intensity and wavelength.

 This could be sufficient natural or artificial light that mimics natural light. 

And although you can employ regular LEDs to support plant growth, they don’t have enough light intensity and wavelength for optimum growth. 

Therefore, invest money in dedicated LED grow lights customized for indoor plant gardening. 

Full Spectrum LED Grow Lights for Indoor Plants: How much will it cost you to operate grow lights? 

There is no exact cost of operating grow lights, but rather it depends on several factors, including usage time, electricity rate, and light wattage. The cost will always increase when any of these factors increase. 

We can estimate the cost of operating grow lights using the formula: 

Cost = LED light wattage X period in hours X electricity rate in kilowatt-hours (kWh)

Final Remarks

We are confident enough that this guide is all you need to grow your indoor plants under full spectrum lights. 

Generally, full spectrum light stands out for its closer characteristics to natural light, especially with wavelength and intensity. 

Also, the light has a high energy efficiency meaning that a larger percentage of the supplied energy turns to useful light. 

And we prefer full-spectrum LED light to other options thanks to their customization options allowing gardeners to control different light aspects.