ARE LED GROW LIGHTS WORTH THE INVESTMENT?
These ‘cool’ products are fantastic for plant growth and very efficient, but a bit pricey
Light-emitting diodes (LEDs) are the hottest thing in interior grow lights for plants.
Well, maybe “coolest” is a better term.
One of the main selling features of LED grow lights is they run much cooler than the competition and are, therefore, more energy-efficient. But LED grow lights are also more costly than conventional grow lights, so the question you need to ask before purchasing them is: Are they really worth the extra money?
A BIT OF SCIENCE
Before one can make a decision on whether to install LED grow lights (or any other grow lights, for that matter) it helps to understand a bit about what they are and how they affect plant growth.
The scientific explanation of how LEDs work can be a bit headache-inducing. What works for me is to think of a single LED fixture as a structure that contains many small semiconductors (diodes) that restrict the flow of electrons whenever the fixture is plugged in and turned on. This restriction causes the diodes to emit lots of light that plants can then absorb and use to convert water and carbon dioxide into sugars.
Other types of grow lights also convert electron energy into usable plant light, but they often aren’t as efficient as LEDs and create too much heat. Granted, heat energy is not a complete waste because plants need fairly warm temperatures to grow well, but poor-quality grow lights typically radiate far more heat than plants could ever use.
The other intriguing aspect of many LED grow lights is designers have been able to “tune” them so they emit the best spectrum of light for plants. Blue and red light are the colours most plants prefer for optimum growth, so many of today’s LED grow lights have strong peaks in both.
Some LEDs emit only red light or blue light, which makes the plants look pretty weird (and even a bit creepy). In one particular greenhouse, I saw row upon row of tomato plants under a sea of red grow lights, which gave the leaves an eerie crimson glow. I felt a bit like I landed on Mars! Fortunately, most of the LEDs for home use are white, thanks to the manufacturers adding other colours to the spectral mix.
WHAT SHOULD YOU DO?
LED grow lights are great because they are energy-efficient, durable, and have tuned light spectra to best meet the plant’s needs. However, there are still many excellent fluorescent grow lights that are much cheaper and still contribute to wonderful plant growth.
The common skinny T5 fluorescent grow light tubes — T means tube and “5” refers to the tube being 5/16 inches in diameter — aren’t quite as energyefficient as LEDs, but they still perform exceptionally well. Spiral fluorescent grow lights are comparable to T5 tubes with respect to light quality and quantity, but they are more compact and can be easily screwed into regular lamp receptacles.
Now, if you still have a few incandescent bulbs kicking around the garage, don’t be tempted to use them as grow lights. They may illuminate a room rather well and provide a nice warm glow, but since they emit only a small portion of usable photosynthetic light, they provide little energy for plant growth.
Perhaps you are thinking of skipping lights altogether. Of course that is an option, but just remember light, rather than fertilizer, is plant food. And with our very short winter days — thanks to our northern latitude — many of our houseplants are pretty much on a starvation diet right now. Some plants can tough out the dark days of winter, but they often look sparse and rather sad for months.
So back to the question. Is it worth paying a premium for LED grow lights over conventional grow lights? Weighing all of the factors, I would say yes, LED grow lights are worth the cost. But I know many people are quite content with their fluorescents, and that’s just fine.
For others, the decision on whether or not to install LEDs might be all about their coolness factor — both figuratively and literally.