How Many Plants Should I Grow Under One LED Light?

Deciding how many plants can comfortably fit under your LED lights can be a pivotal decision in designing your grow facility. When making this decision, there are a few important aspects to consider. These aspects include: the type of crop you are cultivating, their stage of growth, your light’s total output, and the amount of space available.

Herbs, Leafy Greens, Cannabis and More: What are You Trying to Grow?

Firstly, take into consideration the size and needs of your crop. Of course, smaller plants — such as herbs and some edible foods — require less space. This also goes for younger plants, such as those in the clone stage. Other plants may require more room. You will need to ensure your lighting fixture covers enough square footage to deliver the appropriate amount of light to each plant, without any becoming neglected in the shadows.

It is also important to understand what stage of growth the plants are in. For instance, plants in their vegetative stage might respond better to a softer, diffused light, while flowering plants may require a direct, intense light. Arranging your plants according to their evolutionary needs beneath the lighting fixture will prove beneficial.

What are Your Lights Doing for You?

An invaluable aspect of any grow facility are efficient and effective lights. LEDs are able to give plants ample light, and with adjustable features they are able to support any horticulturalist. It is important to remember, however, that not all light is created equal. A basic understanding of Photosynthetically Active Radiation (PAR) is necessary for any grower: this term refers to the amount of usable wavelengths delivered by a bulb, most often between 400 and 700 nanometers. Luckily, LED lights use less energy to create dependable and unwavering light, so you can keep your grow facility well-lit for long hours without the skyrocketing energy bill.

Another feature to highlight is unmatched uniformity, ensuring that each plant under a fixture receives an equal amount of usable light. For example, the Evolve EV360 ProGrowTech lights deliver up to 450 µmol/m2 PPFD delivered in a 4’x4’ lighting pattern, translating to superior uniformity. This 4’x4’ lighting pattern works well with most facilities, and the majority of equipment used in growing is based on this measurement.

Furthermore, cultivating more small plants rather than a few large plants is proven to be more efficient in terms of yield and quality. Keeping the plants short yet healthy, reduces the amount of energy consumed by each plant, allowing more units to comfortably grow beneath each lighting fixture. In addition, growers should take advantage of the ability to manipulate the growth cycle through LED lighting adjustability. Due to the higher plant count, a grower may want to consider exploring propagation through tissue culture.

Start with Square Footage

Of course, any grower has to consider how much space is physically available in a facility. Higher yields aren’t always automatically the result of having several plants squeezed into a small room. It is important to ensure that each plant has an appropriate amount of space and light to flourish. Creating enough space for each plant means higher quality yields in the long run.

…And Then Move into Cubic Footage

But horticulturalists with smaller spaces should not despair! At ProGrowTech, we encourage using grow facilities in the most efficient way possible. That means building up rather than just out. Our LED grow lights are specifically designed for vertical racking — meaning all that vertical space does not have to go to waste. This smart design allows growers to take full advantage of cubic footage. For many, there is no need to invest in a larger space. The end result is towers of happy, green plants, each with enough room and light to flourish.

To conclude, there isn’t an exact formula to follow when determining how many plants belong under each light. We recommend taking the following factors into consideration:

  • Type of plant being cultivated
  • Light fixture’s total output
  • Amount of space available — both horizontal and vertical!