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What Color Light is Best for Seedlings?

Most gardeners know that light is essential for growing healthy seedlings but does it matter what kind of light you use? As a matter of fact, yes!

There are many different lights on the market and some are more suited to growing healthy seedlings than others. If you’re not sure how to figure out what color light is best for seedlings, I’m here to help.

I’ll go over the differences between the different colors of light and what they do to help you figure out what type of light to use. To make it easy for you, I’ll also recommend some grow lights that have the best color light for seedlings.

Seedlings under a grow light. Have you ever wondered what color light is best for seedlings?

Isn’t all Light the Same?

You may be wondering, “Why do I even need to figure out what color light is best for seedlings, isn’t all light the same?” And the answer is no, all light isn’t the same. Let me explain.

The color spectrum of visible light ranges from red to violet. It’s the same as the colors we see in a rainbow. Red, orange, yellow, green, blue, indigo, and violet. These different colors have different wavelengths, ranging from 400-700 nanometers.

Scientists talk about light and color in nanometers because it’s more precise than just saying the name of a color. Anyone who’s tried to pick out paint colors knows there are a hundred different shades of blue, and many of them look the same!

The wavelength of blue light is between 450-495 nanometers. Colors like 465 and 470 would look pretty much the same to us but they’re actually different colors. Thankfully, a high level of precision isn’t necessary to figure out what color light is best for seedlings. For our purposes, blue is blue, and red is red!

Kasey's seedlings under grow lights.

The Color Spectrum of the Sun

Sunlight includes the entire visible spectrum of light. With all of the colors combined, sunlight looks white or very pale yellow. We only see the different colors in light when light is separated, like when a rainbow forms.

Outdoor plants receive a complete spectrum of light every day. They use this light to photosynthesize, turning the light into energy they can use to grow.

Indoor plants don’t have the same access to sunlight so indoor growers need to provide supplemental lighting to keep plants healthy and growing.

So what color light is best for seedlings? Let’s look at what the different colors of light do to help us find out.

Red Light

On one end of the light spectrum range, you’ll find red. Red light has the longest wavelength of all of the colors. It’s important for photosynthesis and for helping plants grow tall. Plants use red light when producing flowers and fruit.

Blue Light

On the other end of the spectrum, you’ll find blue and violet. Blue light is important for helping plants produce chlorophyll.

Effective chlorophyll production makes leaves lush and green. Plants need blue light to grow thick, sturdy stems and healthy leaves.

Green Light

Green and yellow light are in the middle of the spectrum. Some people say that green light isn’t important for plant growth but studies have shown that green light is beneficial for helping plants grow.

Green light may penetrate deeper than red and blue light, improving photosynthesis.

What Color Light is Best for Seedlings

Closeup of an LED grow light next to a plant leaf.

Since sunlight is what plants naturally use to grow, the best color light for seedlings is the color that best mimics sunlight. The light from the sun includes all colors on the spectrum, so a full spectrum light is ideal.

Full spectrum lights are sometimes called white lights but not all products with the name “white” or “white light” include the full spectrum of light so look carefully at the labels when choosing a product.

Full spectrum lights are also called “broad spectrum”. These types of grow lights include all colors of light.

The Best Color Light for Seedling Growth

Initially blue light is important to help plants grow strong and sturdy. Seedlings need blue light in order to grow into hearty, robust plants.

The Best color Light for Plants

As they grow, plants use more red light. Since red light is important for flowering and fruit production, it’s essential as plants mature.

One Color isn’t Enough

No plants can grow well with just one color of light. They all need different colors of light to meet different needs and reach their full potential. That’s why the best light for seedlings is full-spectrum light and not just one color.

The Best Type of Lightbulb For Seedlings

A grow light bulb over indoor seedlings

There are many different types of lights. The most energy-efficient source of artificial light for seedlings is LED lights. LEDs are effective at converting electricity into light so they don’t use as much energy as incandescent and fluorescent lights.

They also don’t get as hot as other lights so there’s less risk of burning the plants.

White LED lights contain the full color spectrum.

Does Light Intensity Matter?

Yes, light intensity makes a difference.

Plants get most of their energy from light. The intensity of the light is a big factor in how much energy plants can absorb. Higher intensity means more energy so in general, higher-intensity lights are better because plants will be able to get more energy.

A seedling growing toward an overhead grow light.

How to Use the Best Color Light For Seedlings

Figuring out what color light is best for seedlings is just one step in ensuring your plants have proper light. Using the lights effectively is also very important.

When to Start Using a Grow Light

Plants need light as soon as they sprout. Once you see those little green shoots coming up, it’s time for a grow light!

How Long Should Seedlings be Under Light

The right amount varies depending on what type of plants you’re growing. On average, plants should be under a grow light for 12-16 hours a day.

Too much light isn’t always better. Plants need a restful period of darkness, just like we do. Be sure to turn the grow lights off for at least eight hours a day.

How High Should the Lights Be?

An adjustable grow light above newly sprouted seedlings.

This also varies depending on what type of grow light you’re using and what type of plants you’re growing. Check the instructions on your grow light to see what’s recommended.

If you’re using an LED light, about six inches above the top of the plants is usually good.

For more information on how to use grow lights effectively, check out the Complete Guide to Seed Starting Lights.

The Best Indoor Grow Lights

Here are my top recommendations for indoor grow lights that offer the best color light for seedlings.

Hoss Tools Hanging Light Kit

Hoss adjustable hanging light kit.

This Hanging Light Kit includes two LED light bulbs that are 36 inches long. The light rail that holds the bulbs has several options for placement, so you can keep the lights close together or spread them out.

The hanging kit comes with carabiners and a pulley system making it easy to hang and adjust the height of the lights.

You’ll need a stand or a rack to hang the lights from.

Mars Hydro Full-Spectrum Grow Light

MARS HYDRO 2022 New TS600 100Watt LED Grow Light 2x2ft Coverage, New Diodes Layout Full Spectrum Grow Lamp for Hydroponic Indoor Seeding Veg and Bloom Greenhouse Growing Light Fixtures Four for 4x4'

This Full-Spectrum Grow Light has a square shape to provide excellent coverage for your plants. The light has a cooling system to keep it from getting too hot. It includes a hanging kit with a pulley system for easy adjustments.

You’ll need a stand or a rack to hang the lights from.

Hoss Tools Seed Starting Light Kit

Hoss indoor seed starting light kit

This Seed Starting Light Kit includes seed trays to help get you started. The canopy is adjustable so you can raise or lower the light as needed. It’s quick to set up and easy to use. The kit is self-contained and doesn’t require anything else to hang the lights on.

Phlizon Full-Spectrum Grow Light

Phlizon 900W LED Plant Grow Light Full Spectrum Daisy Chain Plants Light Double Switch Grow Led for Indoor Plants Veg and Flower-900W

The full-spectrum grow light from Phlizon comes in a box shape. It has a double cooling fan system to keep the lights cool and extend the life of the bulbs. It comes with a hanging kit and pulley system making it easy to attach to whatever stand or shelf you have.

Like with some of the other lights, you’ll need a stand or a rack to hang the lights from.

Want More Recommendations?

If you’d like to see some more great options, we’ve got you covered! For more recommendations, check out the Best Grow Lights for Indoor Plants and Where to Buy Grow Lights.

Final Thoughts on What Color Light is Best for Seedlings

A grow light used for houseplants.

I hope that answers your questions on what color light is best for seedlings! To learn more about indoor gardening and starting plants from seed, be sure to visit the Seed Starting page for lots of blog posts.

We’ve put together a ton of resources for you, from how-to guides to product recommendations and so much more. Whether you’re a beginner or a seasoned gardener, you’re sure to find some helpful tips to get your seedlings off to a healthy start.

Shopping for your garden can get overwhelming, fast. So if you’re looking for advice on garden tools and garden supplies, then you’re in the right place! And if you’re looking for a unique gift for a loved one, how about a gardening gift?