How many LED lumens Per Plant – The Precise Amount

(Last Updated On: October 20, 2021)
How many lumens per plant led
How many lumens per plant led

What is the precise amount of lumens every plant needs? How Many Lumens Do LED Grow Lights Produce?

One of the most important factors in indoor growing is light. The right amount of light, at the right time, can make all the difference between a successful grow and a failed one. That’s why it’s so important to understand how many led lumens per plant you need for your specific setup before you start shopping for lights!

LED grow lights are becoming increasingly popular among growers. LED lighting is perfect for greenhouses, grow tent and any other controlled environment where plants can flourish without natural light or sunlight.

The main reason that LEDs have become so popular amongst gardeners is their low energy consumption compared to traditional HID lamps. They also produce less heat which makes it easier to maintain a good climate in the grow room. With such great benefits, it is important for growers that they use as much light as possible on their plants and here we will look at how many lumens per plant led you need.

What Does Lumen Mean?

What Does Lumen Mean

The lumen is the standard unit of luminous flux, a measure of the total “amount” of visible light emitted by a source. The surface brightness of an extended light source varies with the square of its distance from the observer; in other words, an object will appear four times as bright when it is twice as close to you.

The SI definition refers to “the candela as a unit of luminous intensity“, that is, essentially, how bright something appears when viewed at a certain angle and distance. It’s not directly related to color or wavelength; if two objects are described as having equal luminance (brightness), they must have identical spectral distributions.

Simply put, a lumen is a standard unit that defines how bright an object appears. Luminosity is the actual brightness of an object independent of distance, angle, or time of day.

Difference Between Watt and Lumen?

Watt is a measure of the amount of power that something uses, whereas lumen is a unit for describing how much light an object emits.

Lumen defines how much light an object emits. Watts define the power consumed by electrical devices or other objects, like heaters and lamps. Watts can be defined as joules per second.

A 100-watt heater might warm a room 1 meter squared, over the course of 1 hour; this would use 100 joules of energy. The lumen measures the amount of light coming from something. If you have two different light bulbs with equal watts (for example, 100 watts), one bulb could emit more lumens than another (perhaps 700 lumens compared to 400 lumens). This means that the first bulb is putting out more total light than the second.

How Lumens Relate to Plant Growth

When it comes to indoor growing, a common assumption is that a higher lumen number on a light bulb means better plant growth. This belief is false and could be potentially dangerous if taken as truth.

Lumens are used to measure how much light falls onto something from any given direction, not the amount of energy going towards photosynthesis. This means that lumens are used to measure the brightness of a lamp, not its efficiency.

The amount of energy available for photosynthesis is measured in watts or joules per square meter. Watts can be thought of as how powerful electricity coming out of the light bulb is and it would be equivalent to measuring horsepower if using an engine to power a light bulb. Joules per square meter can be thought of as how much gasoline comes out of the engine, with one joule being equal to a single watt at one second.

A plant’s growth is affected by both the time it spends in darkness and the amount of energy that goes into photosynthesis. So if a plant would spend 3 hours in darkness for every hour exposed to light with half the energy of another lamp, it will actually do better than the other lamp.

So, to summarize, if you provide too many lumens for your plants, it will do more harm than good. There’s an optimal amount for everything.

The Relationship Between Color Spectrum and Plant Growth

color spectrum and plant growth

A plant’s health is largely dependent on the light it receives. Light with wavelengths in the 400-700nm (1 nm = 10−9 m) spectrum, known as photosynthetically active radiation, accelerates plant growth.

However, wavelengths that are shorter than 400nm or longer than 700nm hinder the growth of many plants. This inhibitory effect of light wavelengths outside the photosynthetically active range is known as the PAM effect.

It is important to consider that plants predominantly receive and absorb light within the photosynthetically active radiation spectrum; therefore, this range should be taken into account when designing lighting systems to facilitate plant growth.

It is impractical to control light wavelengths in the air around us, so many researchers are studying how plants themselves respond to different colors of light, which can be regulated.

The National Aeronautics and Space Administration (NASA) has spent years producing research about color spectrum effects on plant growth. Plants grown under red or far-red light wavelengths are smaller than plants grown under green light because far-red light inhibits the growth of some plant tissues.

Therefore, researchers have concluded that greenhouse lights should emit only wavelengths of 400nm or below. For example, if white LED lighting is used in a greenhouse environment for indoor growing where maximizing photosynthesis is the primary goal, greenhouse growers should consider using lighting that does not emit wavelengths beyond 400nm.

Although there are many factors to consider when growing plants indoors, color spectrum is one of the most important factors to take into account. If you want your plants to grow quickly and healthily, use proper lighting.

How Plants Use Light? 3 LED Spectrums [Full Breakdown]

How many lumens do LED grow lights produce?

The amount of lumen produced by grow lights varies depending on the type of light. HPS lights are usually one of the most inefficient types of grow light. On the other hand, LED lights are the most efficient ones.

On average, HPS grow lights produce up to 100 lumens per watt. On the other hand. LED grow lights can produce up to 300 lumens per watt.

Grow light lumens chart

Lumens are a measure of brightness, which is an estimate of how many photons per second are emitted by the lamp. The lumen unit was not intended to be used as a measurement for plants or plant health but it can be helpful in understanding grow lights and choosing what type will work best for your plants.

It is a hot topic these days, especially when it comes to LED grow lights. The issue with this is that not all plants are grown equal and therefore require different levels of light intensity in order for them to thrive.

The required lumen for a plant remains the same regardless of the light you choose. But depending on the light type, you will need more or fewer lights. The following table provides some rough guidelines on how many lumens per plant led you can get from different types of lights.

Bulb type →    
Lumens ↓StandardHalogen  CFLLED
45040W29W9W8W
80060W43W14W13W
110075W53W19W17W
1600100W72W23W20W
Avg. Life1 Year1-3 Years6-10 Years15-25 Years
Savings0%Up to 30%Up to 75%Up to 80%

So, let’s say your plant needs 2200 lumen. In order to get the same amount of lumen, you will need different amounts of different types of lights with different wattages.

  • 2x75W standard lights
  • 2x53W halogen lights
  • 2x19W CFL lights
  • 2x17W LED lights

How Many LED lumens Per Plant

Plants require light for photosynthesis, the process by which plants synthesize carbohydrates from carbon dioxide and water.  Plants grow towards sunlight, so there is an ideal amount of light intensity.

The amount of light required is different for different plants. But we will try to give you a brief idea about how much lumens you should ideally provide for your plants.

  • Ideally, you should provide 7000-7500 lumens per square foot for your indoor plants.
  • 2000 lumens per square foot is enough for low-light plants.
  • You should provide 5000 lumens per square foot for medium-light plants.
  • During the vegetative phase, indoor plants need 2000-3000 lumens per square foot. However, aim for 5000-10000 lumens per square foot during the flowering stage.

Light intensity also changes with the season. During the winter, the sun emits less light so natural light is weaker. Plants need to receive more lumens for indoor or greenhouse cultivation during these months. Potatoes, tomatoes, carrots, cauliflower, broccoli thrives indoors when the winter season arrives.

Lumens and Kelvins for Plant Growth

As mentioned before, lumen refers to the intensity of the grow lights. On the other hand, Kelvin is related to the color of the light. A higher amount of Kelvin means it is closer to natural light.

For an average indoor plant, you should aim for 2000-3000 lumens. The ideal Kelvin for indoor plants number is between 4100 and 6500.

How Many Lumens Does a Pepper Plant Need?

Let’s assume you are growing a pepper plant in a 1m² area. A pepper plant needs around 2500 lumen per plant. An average LED light can yield about 80-100 lumens per watt. So, you will need a LED grow light in the 200-250W range. If you were to grow 12 plants, you would need 12x grow lights with the same output. The pepper plants yield the best results in this setting with 14 hours per day.

How Many Lumens to Grow Tomatoes Indoors

We recommend growing tomato plants inside from seeds only. You can use a light/lights equivalent to 3900 lumens for best results. You should put the light on for around 12-14 hours.

People Also Ask

Are 5000 lumens enough for plants?

In most cases, it is more than enough. Low-light plants need 2000-3000 lumens per plant. 5000 lumens will be too much for those plants. But it is ideal for medium-light plants. Again, in the flowering stage, 5000 lumens may or may not be enough for plants during the flowering phase. So, how many lumens you need varies in different situations. Hence, there is no straightforward answer to this question.

Are 1600 lumens enough for plants?

In most cases, 1600 lumens will not be enough for indoor plants. You need at least 2000 lumens for optimal growth.

Are 800 lumens enough for plants?

Simple answer, no. It’s too low for any type of indoor plant.

How many lumens do you need to grow plants?

If you can manage a bit of sunlight daily, it’s ideal for your plants. But if you cannot, provide 2000-10000 lumens per plant depending on the type of the plant and the phase it is in. All of these have been discussed in the article already. Give it a read!

How many lumens do houseplants need

On average most houseplants need around 2000-3000 lumens per plant.

How many lux for indoor plants

Lux is a unit used to measure the amount of light that falls onto a surface. You need to provide different types of lux depending on the type of light you are using. We will not talk about LED lights here because their spectrum varies greatly and is hard to pinpoint.

HPS lights (14 hours/day)

  • High-light plants need 40000 lux
  • Medium-light plants require 20000 lux
  • Low-light plants need around 12000 lux

Fluorescent lights (14 hours/per day)

  • 37500 lux is required for high-light plants
  • Minimum 19000 lux is essential for medium-light plants
  • At least 11000 lux needed for low-light plants

MH lights (14 hours/per day)

  • You need to provide 35000 lux for high-light plants
  • You should provide 17500 lux for medium-light plants
  • Low-light plants require 10000 lux

Final words

Growing plants with grow lights are tricky. But if you want to do it, you need to do it properly. You need to provide the right amount of light with proper wattage, lux and lumen.

Now you know how many lumens per plant with LED light is required. We have discussed everything you need to know about lumens as a grower. Go through the article properly and utilize them. You will not be disappointed.

If you have any questions, let us know. We will like to answer them.

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