How to Choose Grow Lights

Indoor gardening is proving to be rewarding more than we expect. More people are tuning in for how it makes them feel. Plants make you happier, nurturing them gives you meaning, and seeing them grow is achieving.

The only hurdle one can encounter with indoor planting is setting up the proper environment, largely depending on grow lights. So, how do you choose the grow lights?

In this article, we’ll probe into that topic, but first, let’s clear away some questions you might ask about the grow lights.

Grow Lights and Regular Lights, What’s the Difference?

Lights differ. Some light sources are specific to a certain wavelength of light, and not all of these wavelengths are suitable for the plants to grow. Plants need a source of light that supports the photosynthesis process.

Regular light is energy sufficient and easy to find, the spectral wavelength is narrow and it doesn’t support the photosynthesis process. Grow lights help plantations by providing a certain range of heat and wavelengths.

Grow lights are used by both regular people and professional growers to encourage the plantation process. Since they provide certain spectral wavelengths provided by the sun, they’re useful to get the seeding phase started. In other words, your plants will get a concentrated dose of proper lighting that gets the plantation process started nicely.  

Are All Grow Lights the Same?

Grow lights are devised to deliver only the wavelengths that your plants will use. Since each phase of plantation requires certain wavelengths, the grow lights come in different types.

In the early process of plantation, grow lights that deliver within the blue spectrum are the most suitable, because their wavelengths are short and warm. When used, a significant change in the growing and maturing phase happens. 

Now that the plant is mature and ready to produce, we’ll need a different type of light. At this stage what the plant needs is longer and cooler wavelengths found in the red and orange part of the light spectrum.

When you’re out buying grow lights you’ll find them labeled: 2700K or 4000K. This is the light temperature.

Sometimes, the UV is also used sparsely to protect the plants from bacteria and to help in finalizing the process, right before harvesting.

How to Choose Grow Lights in 7 Steps

Decide On What You Want to Grow

The type of grow lights that you’ll choose depends on what plants you want to grow. For example, flowers and fruits need the high-output LED lights to simulate sun conditions.

Edibles require more light, so if the indoor light levels are low, you’ll definitely need a grow light. Fruiting plants, such as tomatoes and lemons, need the highest level of light possible to be able to produce.

 If you want to grow leafy greens, such as lettuce and spinach, you don’t need high levels of light. These plants can grow perfectly in shady parts, or with a light source farther away from them. Meanwhile, all flowers and fruits with large roots love the sun, so having a proper grow light is necessary.


Different areas indoor have different levels of light, thus affecting the plants’ ability to grow. The average window can provide low/medium lighting levels. In addition to the window size, another decisive factor is the exposure.  

Southern-facing windows will provide a good amount of indirect light in winter, for most of the day. Whereas, north-facing windows will offer low levels of light and these conditions don’t suit most of the sun-loving vegetables.

It goes without saying that the more your house is exposed to light, the better you’ll be at growing indoor plants.

So, be aware of your light sources, how much light is allowed, given the surrounding buildings,  and how far is the plant from light sources. All these factors should be considered when choosing a grow light.


Another major aspect to consider is the planting area design. Will it be a single shelf? An entire room? When planning, make sure to put the trays around 8 inches apart to allow for growth and maintenance. It’s important to consider this early on because the amount of grow light you’ll buy must be sufficient for the area you’re planning to use.

When it comes to the lights’ placement, we recommend that they be hanging over the plants, as this closely simulates the sunlight. This arrangement allows all sides of the plant to be subject to the light source.


Like buying anything else, the budget for grow lights can vary greatly. Some lights may cost as little as a couple of dollars. Some growers choose to build a setup that costs thousands of dollars. Decide on your budget and your purpose for growing indoor plants.

Lighting Types

The lighting sources available in the market differ in the way they eliminate certain light on the spectrum. They give the plant what it needs. As we mentioned earlier, you can choose the bulb that suits you based on the label it has. A 6500K is better for sun-loving plants, such as vegetables. 

LED Light

This type is relatively new. While it provides a huge amount of light, it consumes minimal energy. They’re budget-friendly in the long term. They’re also considered the most durable since they don’t require frequent maintenance. LED lights can last up to 50,000 hours of lighting, making it the most long-lasting type of grow lights. Moreover, they can be adjusted to emit a certain wavelength.

LED lights are no trouble when they’re placed close to the plants, they’re cool, they won’t burn or ruin them. This means that you now have more room space to plant more or use for different purposes.

However, a downside of this type of lighting is that it doesn’t provide heat. Some plants need a certain degree of heat. Also, at first, the setup can be expensive, but as time passes they prove to be the most cost-efficient since they outlive the other lighting types.  

Fluorescent Light

Since fluorescent lights don’t emit much light, they’re usually applied in the early phases of plantation. They’re the most commonly used since they exist in a variety of sizes and outputs.

The two most common types are:

Long Tubes

They’re usually placed parallel to each other in a panel or a box. Since they’re cool in temperature, they can be kept close to the plants.

Compact Lamps

These are the familiar short and twisty bulbs. They’re famous for their efficiency and long lifespan.

In general, fluorescent light costs less. However, it isn’t as durable as the previously mentioned LED lights (approx. up to 10,000 hours). For experienced growers, it’s used as a secondary light. It’s also suitable for small plants and those in the growth face, since it’s not as strong as the LED lights.

HPS Light

This option is best for areas that are completely derived from natural light. It’s most suitable at the flowering/maturing phase. This type of light has proved its consistency over the years. 

However, it still comes with some drawbacks. First, they can’t work on your regular house electricity. They need a ballast to operate. They are also not as durable as the LED lights. Another major drawback is that they produce a lot of heat, which means that plants can be harmed and that ventilation is required.

How Many Do You Need?

Let’s roughly calculate how much light is needed. Usually, one needs around 30-50 watts per square foot.

Doing the math, we can assume that you’re planting 10 square feet, so: 30*10= 300 watts of light is what you need for this area. 

Now you can go and shop for the type of light that will give you the required amount of watts. 

What is important is that you keep in mind the other factors affecting the environment, such as the room set-up, the natural light, and the reflector…Haven’t we told you about that yet?


After deciding on your type of lighting, it’s vital to include a reflector in your setup. Grow lights spread out the light they emit. So some light will be lost, missing the sides of the plant.

A creative solution for this is to use a reflector. This device reflects back those light beams that were almost lost, boosting the efficiency of the whole setup.

To Conclude

The key to productive indoor gardening is to simulate the conditions of outdoor plantations, and part of this simulation is not forgetting to turn off the lights. Just as the sun goes away, you need to give your plants a chance to break down that energy. Just like us, darkness is as important as light for plants’ growth. 

So, before deciding on the type of lighting, make sure you understand what your plant needs and how much that matches your budget.