Updated at: 06-03-2023 - By: Sienna Lewis

A growing light can’t be evident, so remember that it’s only needed when the existing light intensity isn’t appropriate and the growing plants are in need of it. Auburn University’s Office of Sustainability has cited greenhouses as a benefit since they allow for complete control over the environment. When it comes to one of these scenarios, you must know how to use artificial light correctly.

Farmers no longer have to be concerned about extreme and unpredictable weather, thanks to greenhouses, which allow them to remain productive all year round and triple agricultural yields, as an example of this To ensure this remarkable accomplishment, it’s critical, though, to become familiar with the needs of your plants. Here is a breakdown of when to utilize a greenhouse grow light.

When To Use A Growing Light In A Greenhouse Correctly

Supplementation needed

Our knowledge of photosynthesis is based on the fact that plants require light to function properly, thus a successful greenhouse should also give it. Depending on the time of year, the greenhouse may not require artificial lighting, according to Cornell Information Technologies. However, in rare situations, this might lead to temperature issues that negatively impact plants.

Guide to Greenhouse Grow Lights - Greenhouse Info

Since greenhouse temperatures can fluctuate, cooling systems and reduced light levels are employed. As a result, there may be a dearth of light in your home. The plants will benefit from a growing light in this situation.

Another example that dictates when to use an organic light in a greenhouse is during the winter months. In the Northeastern and Northwestern parts of the US, the cloudy conditions affect the amount of light that could get in the greenhouse. Use a growth light for this.

Young plants vs. mature plants

Another example that dictates when to use an organic light in a greenhouse is during the winter months. In the Northeastern and Northwestern parts of the US, the cloudy conditions affect the amount of light that could get in the greenhouse. Use a growth light for this.

Another example of when an organic light should be used in a greenhouse is during the winter months. The gloomy circumstances in the Northeastern and Northwestern areas of the United States limit the quantity of light that can be absorbed by greenhouse plants. This is where a growth light will come in handy.

In order to ensure that all of your plants’ leaves receive the same amount of light, you may need to increase the intensity of your growing lights. In addition, the sort of plants you’re growing in a greenhouse will have an impact on the amount of light you’ll require. During the months with little natural light, for example, you’ll need a growth light for plants entering the fruiting or flowering phase.

The end of October is the traditional start of tomato harvest in North America, necessitating the usage of a growth light. Plants produced for their vegetative portions, on the other hand, may not necessitate a growing light because they are already in the growth stage mentioned above. Even yet, the low light levels of winter may necessitate the use of a growing light to maintain plant development.

How Long Should You Use A Growing Light In A Greenhouse?

Each plant has different light requirements, as previously discussed. A greenhouse grow light’s lifespan is determined by the plants it’s used to support. Plants can be divided into groups based on how long or short their days are, making it easier to arrange the length of the growing light period.

When the day is long and the night is long, long-day plants will thrive, while short-day plants will thrive when the night is short. There are plants that flower even in the fall because of this. You can use an organic light to lengthen the day for plants that need short days, such as herbs, which are grown for their vegetative phase.

The amount of light your greenhouse is able to provide is a major factor in its overall performance. Be aware of your crops’ specific lighting requirements while also keeping an eye on the other necessities they require to thrive. It’s also worth mentioning that if your crops aren’t properly spaced, they may not receive enough light.

Can You Have Too Much Light In A Greenhouse?

Maintaining proper lighting conditions in the greenhouse is critical to the health of the plants, since too much light equals to too much heat energy. Light and temperature are critical in this area of a greenhouse’s operation. You can utilize cooling systems, evaporative cooling, and shadings to keep the greenhouse temperature under control if there is too much sunshine.

Types Of Growing Lights

There are three basic types of growth lights, even though they all serve the same purpose, which is to either complement or completely replace natural light in urban farming. First, let’s speak about the several types of growing lights that can be used in a greenhouse.

Fluorescent growing lights

Tubes, CFLs, or both are available as options for these growing lights. Veggie and herb gardens benefit greatly from the illumination provided by these lightbulbs. How effectively light is distributed among plants is directly related to how far away the fluorescent bulbs are from the plants.

HPS lights

Experts only use HPS, or high-pressure sodium, lighting. These yellow, heat-emitting bulbs have been in use for more than seven decades. A reliable, stable light source is difficult to achieve using this technology, which is available on the market.

LED lights

The most popular type of light source is an LED. Compared to its two rivals, they are more efficient in terms of light and energy consumption. Aside from the fact that they emit almost no heat, these lights excel in focusing light. CFLs, on the other hand, are more affordable, but their efficiency is limited to a narrow range of wavelengths.

Growing Light For Your Greenhouse

The best time to employ different kinds of growing lights is now that you’ve learned about them. You’ll learn about the precautions you should take before utilizing these greenhouse lights in this section of the site.


The fast-changing weather and unpredictability of the climate could lead to inconsistencies in sunlight. Due to their need for adequate light to generate their food, your greenhouse plants may suffer as a result of this irregularity.

The use of growing lights in the Northern regions during the long and gloomy winter days is highly beneficial. Although sunshine isn’t always available, these artificial devices can encourage the growth of your florae and provide them with the proper amount of photons.

Indoor greenhouse

In certain cases, greenhouse-lovers prefer to maintain their plants in their homes. As a result, they rely on growing lights to provide light to their plants.

Using a growing light system if your greenhouse is located indoors or in a region that does not receive adequate sunshine is recommended. Your greenhouse would be more efficient if you continued to grow plants.


In order to benefit from a product, you must know how to use it. Prior to employing these lights in your greenhouse, you should take into account the needs of the plants there.

The spectrum of visible light is made up of all the hues of the rainbow. In order to boost their growth, plants make use of the red and blue ends of the spectrum. If you want to grow your plants, you need to do more than buy a cheap lamp to mitigate and mimic sunlight.

Use of blue and red light bulbs is strongly suggested because they are more energy efficient than standard white or yellow bulbs.

Because they are man-made, it is essential that you maintain track of the time your plants spend under a growth light. Most flowers and vegetables need at least 12 to 16 hours of sunlight each day. The plants’ respiration cycle is dependent on darkness, thus going above that limit could throw their cycle off.

Proper installation of this equipment is also necessary to ensure that light is distributed evenly throughout the greenhouse. Growth will be slowed and development will be enhanced if the plants receive insufficient photons.

Finally, make advantage of low-heat greenhouse lights. According to research, heat and high temperatures can have an impact on the vitamins and nutrients in your plants’ tissues. Because LEDs emit no heat when they are turned on, it would be beneficial if you used them.

How To Use A Growing Light?

Your plants’ growth depends on knowing when to utilize a grow light in a greenhouse. We’ll now go over some pointers and procedures for working with a grow lamp.

#1 Use a light timer

In some cases, you may not need to keep your greenhouse open 24 hours a day. It is suggested that you use a light timer to regulate the on/off cycle of your lighting system.

#2 Position the lights properly

As a general guideline, keep your plants one to three feet away from low-intensity light discharge growing lights. High-luminosity lights, on the other hand, should be four to six feet apart. Check and adjust the lighting to meet the specific requirements of your plants.

Also, make sure that the lighting is evenly spread by positioning the lights in the right spot. As a result, if you have a larger greenhouse, you’ll need a bulb that has higher wattage and provides more light for your plants.

Combining Sunlight and Grow Lights: Supplemental Greenhouse

What is a grow light (or plant light) anyway?

Humans and plants use light differently. Light is a source of energy for plants, who use it to photosynthesise and grow. It’s a grow light’s job to provide plants with the proper spectrum of light they need to thrive.

Can I just use a regular light bulb as a grow light?

Ordinary light bulbs may produce a few of the plant-specific light waves needed for growth, but they are largely ineffective. Because they’re meant to brighten our houses, this is the reason. The spectrum, strength, color, and even the shape of a grow lamp all contribute to the amount of energy it gives a plant it needs to grow to its full potential.

Some grow lights may resemble typical household globes in their appearance. If you’re concerned about how light is seen by the human eye, keep in mind that the plants have a very different take on it.

How long should a grow light be left on?

The amount of time a grow light is on depends on a variety of factors. the type of lighting you’re employing, the location your plant is in, and what you intend to use the light for (eg, foliage growth, vegetables or flowering).

Instructions should be included with the lamp you choose. Here are a few guidelines to keep in mind as a general guide:

  • Grow lights need to be on for at least eight to ten hours a day to be successful. Depending on the circumstances, this can go up to 16 hours. It makes sense to use energy-efficient LED grow lights when they have to be on all day.
  • Ensure that a grow light is always placed above the plant. This acts as a substitute for the sun’s rays. For plants, it is always ideal to place them above the light source.
  • Make sure your grow light isn’t touching your plants or going too close to them if it’s heating up.
  • As a general rule of thumb, the more powerful the grow light, the better the results for smaller plants and those that like a more shady environment.

Where Should I Position My Grow Light?

Remember that in nature, a plant receives sunlight from the sky.

Many individuals utilize grow lights attached to the plant’s base as a replacement for their overhead lighting or even in a lamp with a shade close to the plant itself. Unfortunately, this isn’t going to be very good for the plant, despite the fact that it may look nice in your room.

For grow lights to have an impact, they must be placed very close and unhindered to a plant. Indoor plants, particularly those grown under grow lights, can begin to tilt toward the windows in search of more light.

You should place a grow lamp above your plant so that it can grow upwards as nature would have done.

What distance should a grow light be from my plants?

The closer the plant is to a grow light, the more beneficial it will be. Higher light intensity can be achieved by placing lights nearer to plants.

The light’s brightness and color temperature have a significant impact on how far the beam can travel. If you’re concerned, I’d recommend starting with a distance and gradually increasing the light intensity to watch how your plants react.

When a light is placed nearer to a plant, it tends to have a smaller field of view. The light can be placed closer to the plant if you’re only interested in illuminating one (which means more light for the plant).

Consider the bulb’s length if you plan to light a few plants. Multiple plants may need placing the grow light farther away. Make sure to remember that the further away the grow light is from the plants, the less light they’ll be receiving.

What colour grow light is best?

Many grow lights are available in a variety of colors. Different light wavelengths are used for various purposes by plants, such as flowering and fruit production.

A broad spectrum bulb would be a good addition to your indoor plant grow light if you’re seeking for leafy, green growth. For the best results, search for a full spectrum grow light (white ones look better than colored ones) that provides the whole range of light that plants require!

For typical indoor plants including Fiddle Leaf Figs, Philodendrons, Calatheas, Peace Lilies, and Palms, a broad spectrum grow light is ideal.

Some of the most commonly used grow light colors include red and blue as well as the combination of the two. Red light promotes flowering, whereas blue light aids in the growth of the plant’s roots. However, if a plant receives an excessive amount of a single color, it may become distorted or out of proportion.

So, What Grow Light Should I Use for my Indoor Plants?

Choose a broad spectrum LED white grow light for your indoor plants if you want them to stay green and leafy all winter (or in a darker home). These can be a little difficult to find, so I propose this Soltech Solutions Aspect pendant lamp.

This product comes in two different sizes: a little one and a large one. Smaller plants that prefer low or medium light levels should use the small. If you plan to grow larger indoor plants or want to be able to hang the light higher over a collection of plants, go with the larger size light.

And to top it all off, Soltech has offered a discount code to my readers! Get 15% off your grow light with the code dossier2021.

Using a timer for grow lights

Since grow lights must be on for at least eight to ten hours every day, you may want to consider purchasing an automatic timer. ‘ When you set a timer, the light will come on and go off according to your specifications.

You may even purchase timers controlled by an app, making it feasible to turn your grow lights on and off from any location. If you’ve forgotten to turn them off at night or there’s a storm approaching, this is a great solution.

The plants that we bring into our homes become an integral part of our lives and our decor. As a thank you for all they do, I’ll bet you want to spoil them rotten so that they can flourish in your home.

You can’t beat the feeling of watching your plant babies flourish in your care. Using grow lights, we’re able to achieve exactly that.

In low light, plants are more likely to show signs of distress. Here are 8 symptoms that your houseplants need more light if you’re not sure if they need additional light.

Do not hesitate to contact me if you have any questions about grow lights. Join me on Instagram, where I post a lot of plant care advice!

Do You Need Greenhouse Grow Lights?

Photosynthesis, the process through which plants make food for growth, requires light for plants to function. Your plants will grow stronger, healthier, and more resistant to disease if they receive adequate nutrients from the soil and fertilizers, as well as frequent hydration.

The walls and ceiling of a greenhouse are composed of glass so that sunlight can pass through. When the weather is too harsh, you can use it to control the temperature and humidity levels in order to encourage healthy plant growth. If you’re a novice gardener, or even if you’ve been doing it for a long time, this is the best option for you.

A comprehensive Ultimate Guide to Greenhouses should be studied prior to making a kit purchase or beginning a DIY project.

A greenhouse protects plants from the elements, including wind, rain, and cold. Additionally, it shields the seedlings from predators like as animals, birds, and insects. However, for a variety of reasons, getting enough direct sunshine might be a challenge.

  • You reside in a region that isn’t exposed to a lot of sunshine by virtue of where you are. Your greenhouse will be too gloomy during the winter months for the plants to thrive.
  • Your garden is small, therefore you must locate the greenhouse in a location that receives no direct sunshine.
  • A large number of trees in your yard or garden are preventing you from getting enough natural light.

Installing greenhouse grow lights, on the other hand, can aid in plant growth. Consider one of the ten finest beginning greenhouse plants to get you started. An artificial light source that aids in the proper health of a wide variety of plants.

If you’re growing seedlings in the winter, when the sun sets earlier, grow lights can extend the amount of time they’re exposed to light. If your lights aren’t getting enough sunlight during the day, you may either program them to come on after sunset or place them in the greenhouse’s corners. Our tutorial on how to grow a winter greenhouse will teach you everything you need to know about caring for a greenhouse in the winter.

Determine whether or not grow lights are necessary for your plants by learning about their needs. Even if your greenhouse doesn’t get enough sunshine, certain plants require partial sun exposure to thrive. Grow lights are crucial if you’re growing plants that require full sun exposure. It’s possible that your greenhouse is getting too much sunlight. A shade cloth or shade paint can provide relief from the sun’s rays.

What Kind of Greenhouse Grow Lights Should You Get?

In most greenhouses, grow lights are used to supplement the sun’s rays, allowing plants to thrive. Grow lights can, however, become the dominant light source in harsh weather circumstances, so you must be cautious when selecting the proper one for your greenhouse setup. Here is a list of the various greenhouse grow lights on the market.

High-Intensity Discharge

Metal halide and high-pressure sodium lamps, also referred to as HID lighting, are examples of this form of illumination. There are three basic components of HID lighting: a ballast, a reflector, and an LED bulb. Some ballasts are able to transition between MH and HPS bulbs, allowing them to be used with either type of bulb.

Growing with Artificial Light — Bob's Market and Greenhouses

To emit light, the bulb is connected to the reflector via the ballast, which links to the power source. In terms of cost and coverage, HID is the best option. However, you should avoid placing the bulbs too close to your plants, as HID lights are extremely powerful and might burn them.

The blue or cold light produced by metal halide lights promotes bushy growth. Red or warm light from high-pressure sodium lights stimulates the growth of flowers and fruits. In order to foster the growth of various plants, most people use reddish or orange light.

Light Emitting Diodes

LEDs are incredibly durable and are made of a panel of LEDs and a circuit board. It is common for LEDs to come with a fan to disperse heat and extend their life duration. They’re extremely popular because you’re able to adjust the light spectrum based on the plant’s needs.

Induction Lighting

Electrodes are used to transmit power in a sealed bulb in this innovative technique. The metals and gases of a light bulb are heated and activated by radio waves or microwaves.

Induction fluorescents have the advantage of standard fluorescents, but they last longer and promote uniform growth in your greenhouse. The coverage is limited to the area under the light source, but the fixture can last for up to 15 years with no need for maintenance.

Standard fluorescents have their advantages, but induction fluorescents last longer and help your greenhouse grow uniformly. The light source only illuminates the area directly in front of it, yet the fixture can endure for up to 15 years with no maintenance required.

What Problems Can I Face With Greenhouse Grow Lights?

In addition to the numerous advantages that come with investing in a greenhouse lighting system, there are also certain drawbacks that should be taken into account.

Not Enough Light

Growers that don’t have enough lights in their greenhouses risk damaging their plants’ development. In order to reach the sun’s rays, plants will bend and grow.

Seedlings, blossoms, and fruits will be deprived of vital chemical activity because plants are attempting to gain more sunlight. The outcome will be plants that are more susceptible to disease and don’t blossom or flower as they should, making them less attractive.

This means that you must ensure that the grow lamp you install has an adequate wattage to meet the needs of your plants. During the growing stage, it should be placed within one to two inches of the seedlings.

The vital photosynthesis process can only be carried out by flowering houseplants when they are located around 12 inches away from the light source. As far as 36 inches away from the grow lights, foliage plants can be positioned. As a vegetable gardener, you’ll need a lot more light exposure. Fruit is produced as a result of this process.

Too Much Light

Plants can be harmed by too much light. Light and water are necessary for plants to produce oxygen and starch as nourishment. The plants convert starch to sugar at night and store it for use during the day.

To encourage rapid development, some gardeners leave their grow lights on all the time, although this can be harmful to the plants’ health. Excessive exposure to light can damage or even kill plants. A minimum of eight hours of absolute darkness should be maintained in order to ensure the health of your plants.

Consider the wattage and distance between your bulb and your plant when choosing a light source. It is possible that a high-wattage bulb will be detrimental to the health of your greenhouse plants. The bulb should not be placed too close to the plants, so that they don’t burn.

When it comes to light intensity, different plants have varied needs. In general, plants that thrive in dry, sun-drenched locations require more grow lights. There is no need to use a lot of grow lights to grow plants that thrive in shady or tropical forests because they don’t get enough sunlight.

Wrong Kind of Light

Choosing the right light for your plants is essential. Blue light stimulates bushy growth whereas red light is more suited for flowering plants in grow lights.

In order to get the most development from your plants, you need to use the optimum HIDs or LEDs. When working with smaller or less robust plants, it’s best to avoid using HIDs because of the high levels of light and heat they produce. It is easier to customize LEDs because you may select the appropriate light spectrum. In comparison to other lighting options, fluorescent tubes are less expensive and produce less heat.

Uneven Distribution

Because of improper lighting installation, even with the greatest grow lights, your greenhouse plants may suffer. As a general rule, 20 to 40 watts of light are required per square foot of greenhouse area for all types of plants.

It’s also important to make sure that all of your plants have equal access to light, so you’ll need to make sure that the larger plants don’t block the smaller ones.

The sort of grow lights you select will be heavily influenced by the size of your greenhouse. In the event that you have a large greenhouse, HIDs are a worthwhile investment because they cover a large area.

Fluorescent lights have the added benefit of being able to illuminate a bigger space while dissipating less heat. They need to be set up such that they completely cover the greenhouse. LEDs can be used in larger greenhouses if they are equally distributed.

How Long Should You Keep Grow Lights Be On?

Despite the fact that plants require light to thrive, they also require time to relax. Your plant’s physiology needs darkness to carry out other chemical activities, so you don’t need to keep the lights on all the time. As a result, a timer should be installed to regulate the amount of time your grow lights are turned on.

When it comes to their daily light requirements, plants can be categorized into three types. To encourage blooming, short-day plants require less than 12 hours of light. These plants can be damaged by too much light. Azaleas and begonias do not require grow lights if they are in a greenhouse that receives enough sunlight during the daytime hours of the growth season.

For proper development, long-day plants require between 16 and 18 hours of daily light exposure. When seedlings are growing, long-day plants, such as vegetables and flowers, require more light.

Foliage plants and geraniums, which are considered day-neutral, require between 8 and 12 hours of light per day, year-round. If your greenhouse doesn’t get enough sunshine in the winter, you may have to utilize grow lights just when the days are getting shorter.


Planning and executing the ideal growth conditions and requirements for each crop is essential to a successful greenhouse. This is one of the most important aspects of growing plants in a greenhouse, so keep in mind that the light intensity isn’t perfect at all times. The depth and duration of growth for each stage of a plant’s life cycle may necessitate specific planning and preparation.