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are leds good for growing weed

However, because of their low price, if you’re new to indoor growing and not sure how often you’ll do it, you may want to invest in an inexpensive HID light at first to test the water.

HID (high-intensity discharge) is an umbrella term under which MH and HPS bulbs fall, which we’ll discuss more below. These types of lamps have a hood that reflects light and bulbs that are enclosed capsules containing a gas, as opposed to bulbs you’d find in your house, which have a filament that heats up.

You can find HID reflector hoods, as well as MH and HPS bulbs at any local grow shop.

HID lights for growing marijuana

There are daylight bulbs and warm white bulbs; the former better for vegetative growth, and the latter for flowering.

These HID bulbs usually contain sodium, mercury, and xenon, and produce a yellow/orange light, and are commonly used for flowering plants. Some growers will start plants under MH bulbs and switch them to HPSs when plants go into the flowering stage, using the same hood. These lights also require a ballast.

Safety

There are many different kinds of lights out there, so it can be daunting to know where to begin. Here’s a guide to four basic types of grow lights on the market and the pros and cons of each.

CFLs (compact fluorescent lamps) are fluorescent lights similar to what you’d find in a school or office building, but smaller. For growing weed, they are usually called “T5s”—the “T” stands for “tubular” and the “5” refers to its diameter, “⅝”.

Are leds good for growing weed

LED technology has only been available on a commercial level in the horticultural industry for around three years. So realistically, they would only have had time to trial a limited number of spectrums that may yield good results for one or two strains/cultivars. We simply have not had the technology long enough to perform the testing needed!

With all of these factors above, how do we answer our initial questions?? Quite frankly, there is no simple answer! Every grow is different – from different: strains being grown, growing climates by geography, style of growers, indoor versus greenhouse, etc. All of these factors will weigh heavy on what is better for you!

Greenhouse Application

There is a lot of information out there on the internet from various growers and lighting suppliers. You can find a contradiction to almost every point you find! Most growers agree that for young plants through the veg stage of growth you will want to have a light source with a good amount of blue light or even white (full spectrum) lighting. The main reason for this is to reduce internode stretching to produce a stockier, healthier plant.

It was only after companies like P.L. Light and Philips* introduced LED fixtures specifically engineered for truss mounting in a greenhouse, that growers really adopted this technology. These products enabled even the indoor grower to maintain some distance between the LED fixtures and the plant canopy, and resulted in production similar to growing under HPS. (*In the United States, Philips has taken the stance that they will not support sales into the cannabis industry as it is not recognized to be legal by the federal government)

HPS or LED: A Key Factor to Consider

What about growing in a greenhouse? From our graph above showing the spectrum of sunlight compared to that used for photosynthesis is there any benefit for using a light source where you can dial in the spectrum to add more blue? The natural light received by your crop in a greenhouse will cover all of your light spectrum needs. So the big question for greenhouse grows should center more around the ROI comparisons between LED and HPS — not about light spectrum needs. This is not something you will hear from light manufacturers of LED lighting. Your LED-only supplier will have you believe you NEED their spectrum specifically!