When it comes to lights, light bulbs, fluorescents, LED grow lights, etc, we are very familiar with the term Wattage (Watt) but hardly ever do we discuss lumens. We want to know how bright the light will be, how long it will last if it is enough for our room size and so on. This is quite different when it comes to plants. Sometimes it doesn’t depend on how bright the light is, or how long the bulb will last but how many lumens will be produced for the plant.
Simple grow lights above plants
This brings us to the following questions: What are lumens? Why are they important to plant growth? And how many do plants need to grow?
IN THIS ARTICLE
What are lumens?
Lumens is described as the total amount of visible light that a light source produces every second. The number of lumens produced depends on the source of light. For example, fluorescents produce 45 to 100 lumens per watt, light bulbs produce 15 to 17 lumens per watt and LED light produces 70 to 100 lumens per watt.
Read more: Beginners guide to grow lights
Why are lumens important to plants?
Light is a basic growing condition for every plant, regardless of the growing location. For outdoor plants, the basic amount of light needed is gotten quite easily from exposure to sunlight but the same is not the case with indoor plants.
Most indoor plants struggle to get sufficient light, so often they are supported by grow lights, LED lights and so on. The light you pick will only favour your plant if it is bright enough to meet the lighting needs of that plant species. So, picking a supplementary light source that offers the number of lumens that is needed for your plant is what makes lumens important to plants.
How many lumens do plants need to grow?
The number of lumens that your plant needs to grow and stay healthy depends on certain factors, such as the type of plant, the size of the room where the plant is, the goal of your growing the plant (that is the yield you want in terms of size, flower and/or seed production, etc).
In reality, there may be no ideal or set number of lumens that plants require to grow, but here is what we found out about the lumen requirements for plants. For plants that require minimum lighting, 2,000 to 3,000 lumens per square foot of the room is ideal and for plants that require more light – 7,000 to 7,500 lumens per square foot is ideal.
