Which Grow Light is Best for Me?

-Cole O’Donnell-

Lighting is perhaps the most important consideration when moving a garden indoors. With so many options on the market today, choosing the right lighting setup for your indoor garden space can be daunting. Whether your intention is simply to keep plants in a state of dormancy, or extend the growing season in order to flower or fruit, there are a number of simple measures that can be taken to ensure success.

When helping guide our customers, we always start with a few basic questions about the growing space – What is the total square footage? Is there any existing natural light? How about ventilation? Knowing the type of plant a customer is working with also helps us choose a light that will provide the right spectrum (and that which is most suitable to that environment) in order to achieve the desired results. The term photoperiodism refers how a plant responds to periods of light and dark, which in the natural environment is dictated by the time of year and season. When a plant is moved indoors, manual adjustments to lighting must be made to trick the plant into knowing when to flower and fruit.

We’ll begin by addressing some differing light systems and their characteristics. There is an abundance of information out there regarding all the differences between T-5 fluorescents, compact fluorescents, LED’s, and LEC’s so the goal here to bring it back to a basic understanding for practical application.

T5 Fluorescents: T5 lighting is a tried and true system of fluorescent grow lighting. T5 bulbs will typically fall into one of two categories; 3,000K (Kelvin) or 6,500K (Kelvin). The 3,000K bulb will be better suited for flowering phases due to its broader spectrum of red and yellow lighting.  The 6,500K bulb is associated with vegetative growth since it emits more blue spectrum. In our experience, using 3,000K lamps in conjunction with 6,500K lamps provides the most complete fluorescent spectrum for the majority of plants’ needs. T5 lights have very broad applications in that they will suffice for most any type of plant or tree while occupying minimal space when compared to many other systems. Additionally, with the ability to now swap existing T5 fluorescent bulbs for T5 LED replacements we can affordably run a more “dialed-in” spectrum designed for the plants’ needs.

Best for: Overwintering houseplants, growing specific types of plants (like African violets or succulents), seed starting and propagation, growing microgreens and wheatgrass year-round

Pros: affordable, easy to add-onto, have their place in the propagation world

Cons: must be disposed of safely (contains trace amounts of mercury), won’t take you all the way through plant cycle

CFL (Compact Fluorescent Lighting): If you find yourself in a situation where space to hang additional lighting is unavailable, or you simply wish to achieve sufficient grow lighting without the addition of any new fixtures, compact fluorescents may be exactly what you’re looking for.  CFL, similar to T-5, typically fall into either a “daylight” spectrum at 6500K best for vegetative growth, or “soft-white” at 2700K best for flowering/fruiting. With the ability to use CFL bulbs in standard home lighting fixtures, it makes them a perfect solution for those of us looking for a simple, cost-effective method to keep things growing through winter.

Best for: Providing supplemental light for a single plant

Pros: cheap, can be used for houseplants, can fit into any fixture

Cons: Replacement is more involved since you’re buying the whole unit attached to bulb

LED (Light-emitting diode):  Once considered too expensive for the small, home grower and not as high-performance enough for the professional grower, much has changed in the world of LED grow lighting in recent years. With the ability to vary light spectrum mid-phase, a nearly non-existent heat signature, and incredible energy-efficiency, LED lighting has certainly garnered well-deserved attention from the industry.  The minimal heat output makes them perfect for any indoor setting (grow tent to living room), while adding an aesthetically pleasing blue or red glow over your plants. In addition, LEDs provide a more complete, variable spectrum of usable light than many prior systems of the past. Let’s briefly look at what “variable light spectrum” means for the home grower. In the AGRO-LED system, for example, switching between your vegetative spectrum and flowering spectrum is as easy as a flip of a switch.  The additional cost and labor of swapping bulbs mid-phase is completely eliminated with this technology, while adding the ability to run both spectrums simultaneously, creating maximum usable light for your plants.  This makes them a truly great choice when looking to extend your growing season in order to reach a winter harvest, indoors.

Best for: Anyone! Great for flowering and foliage plants

Pros: Energy efficient, can produce full light spectrum

Cons: Light penetration is lower than HIDs, higher initial cost (but coming down!)

LEC (Light-emitting ceramic):  These lights, also known as Ceramic Discharge Metal Halides, are at the forefront of indoor grow lighting technology. With very minimal heat output, and improved energy efficiency over traditional high intensity systems, LEC is another great choice when looking to bring your crops indoors. The Sun System LEC315W used with a Philips Master 315W bulb provides a light spectrum suited to run from germination to harvest, making them extremely well-suited for everyone from the enthusiast to the seasoned farmer.  Similar to an LED, the minimal heat signature of this system makes it ideal for any setting from small grow-tents and indoor gardens, to large commercial spaces.  In regards to ease of equipment use, and overall quality of usable light for many different crops, the Sun System LEC315W is my current choice for maximizing a given space.

Best for: Anyone with at least 3×3’ growing area, flowering plants to cacti

Pros: Excellent PAR rating, good coverage for wattage, affordable

Cons: none

Once we’ve selected the proper light system for our environment, its time to dial in the duration side of photoperiodism. While light requirements sometimes differ from plant to plant, an automatic timer makes whatever situation you’re dealing with as simple as set and forget.  Whether going with analog or digital, I always recommend using a timer in conjunction with your light system. This is an inexpensive investment that will eliminate all guess work and the need to manually turn lights on and off throughout use. We spend enough energy on caring for the plants themselves, let the tools do the work in the case of light cycles!

Now we can use this understanding of spectrum and photoperiodism to set our plants and ourselves up for success throughout the year! With an understanding of plants’ needs, and proper equipment in place, there is absolutely no limit to what we can achieve in our indoor grow spaces. With the rapid advancements being made in lighting technology, growing your own at home has never been easier or more cost-effective. The money saved on one season of home-grown vegetables alone can justify and offset costs of even the most sophisticated grow lighting. Just think of how wonderful walking a few feet to your indoor garden for fresh, organic produce will be!