The growing prominence of LED grow lights

Before you go buying an LED grow light, it helps to know what’s available. Currently, there are three main types of LEDs that you can use to grow cannabis, each of which has its pros and cons. The type of LED light you should choose will depend on what exactly you’re looking for, and how much money you’re willing to spend.



  • STANDARD (“PURPLE”) LED







  • COB LED







  • SPREAD-STYLE LED







THE ADVANTAGES OF GROWING WITH LED LIGHTS




We’ve already mentioned that LED lights have several advantages when compared to other types of grow lights, such as HID. Here is a full rundown of why you may want to choose LEDs for your next growing operation.




1. LED LIGHTS ARE MORE ENERGY-EFFICIENT




Compared to HID lights, LEDs are a lot more energy-efficient. They use less electricity, and will cost much less to operate in the long-run. Although high-end LED lights can sometimes cost a good chunk of money outright, the investment is almost always worth it as your savings over time will make up for the higher initial cost. Likewise, quality LED light fixtures will also have a longer life span compared to HID, the latter of which tends to lose performance over time and needs frequent replacement. A good LED light can last you many years with no maintenance needed.




2. THEY RUN COOL




LEDs produce a lot less heat compared to HID lights, which can be a big advantage as you won’t require extra cooling systems in your grow room or tent to keep temperatures optimal. This is especially advantageous if you grow in summer or happen to live in a warmer climate. The downside to this is that if you live somewhere cold, you may now need to consider a heater in the colder months. But as LEDs save you money over time, this can make up for the potential costs of running a heater.




3. WITH LED, YOU CAN MOVE YOUR PLANTS CLOSER TO THE LIGHT




LEDs produce less heat, which means less stress on your plants—so you can move your lights closer to your plantswithout any negative effects. Higher light intensity translates to higher yields!





4. LED LIGHTS REDUCE YOUR WATERING SCHEDULE




With less heat produced by lights, the soil in your pots will stay moist for longer, thus reducing the amount of times you need to water. If you’ve just switched from HID to LED and are used to your plants drinking quite a lot, you now need to be careful with your new watering schedule under LED, otherwise you might overwater your ladies.




5. YOU NEED LESS NUTRIENTS




When you water cannabis plants, you’ll normally do so with an infusion of nutrients. In addition to watering less, your plants will also need less nutes than they would before. In addition to some nice savings on nutrients, the less-frequent watering and feeding schedule will also decrease nutrient buildup, so there’s a lower risk of nutrient lockout and plant deficiencies.




GROWING WITH LED: WHAT TO CONSIDER FOR EACH STAGE OF CULTIVATION




As we touched on earlier, many types of LEDs have a fixed light spectrum that works for both the vegetative (growing) and flowering phases of cannabis. This way, you can just use the same light throughout your entire grow from seed until harvest.




Although this is convenient for most, there are those who want to fine-tune their lights for best results and optimal efficiency in each growing phase. For this purpose, some commercial LED lights have a switch to activate a veg light spectrum or a flower light spectrum. Here are some more factors to consider throughout each stage of growth.




A) LED LIGHTS AND SEEDLINGS




As soon as your seeds have sprouted, your soon-to-be cannabis plant will need light to grow. Compared to more mature plants, however, your seedling is much more sensitive to intense light. Because of that, you should be careful when starting out with strong LEDs.




If your LED has a dimming option, turn your light to a lower intensity. If this isn’t an option, consider moving your lights further up, away from the seedling. On the other hand, ensure that you do not move the lights too far up, as this could cause the seedling to grow spindly and lanky.




Likewise, if your LED has a switch to activate either a vegging or flowering spectrum, set it to veg, where the light normally emits a “cooler” blueish light, which is optimal for this stage. Set your timer to 18 hours of light per day, with 6 hours of darkness.




As your seedling grows taller, stronger, and approaches the most robust part of the vegetative growing stage, you can then gradually increase the light intensity.




GROWING WITH LED: WHAT TO CONSIDER FOR EACH STAGE OF CULTIVATION




B) LED LIGHTS DURING VEGETATION




Set your light to 18 hours per day and 6 hours of darkness. Some growers choose to grow with 20–24 hours of light to maximise vegetative growth.




Monitor your plant’s development; if all goes well, it should grow healthy, strong, and bushy. If it grows lanky and spindly instead, this is likely because your plant is not getting enough light. Increase the intensity by lowering the light toward the plant canopy or turning up the intensity using the dimmer if your light has one.




How long you want to veg your plant will normally depend on how much space you have available. You can technically let your plant grow under 18–24 hours of light as long as you want, but there will likely come a time when you want to switch to flowering, as the plant would otherwise simply grow too big. Know that some cannabis strains can stretch considerably (up to 2x or more) during early flowering. Take this into account upon deciding when to initiate the switch to bloom.




C) LED LIGHTS FOR FLOWERING




Photoperiodic cannabis starts to flower in late summer when the daylight hours naturally begin to diminish. Indoors, the grower is responsible for inducing bloom by setting the light schedule to 12 hours of light and 12 hours total darkness. If your LED light has a flowering switch, turn it to flowering mode.




When you flower indoors on a 12-12 schedule, it is important that the 12 hours of darkness are not interrupted. So make sure that your tent or greenhouse doesn’t have any light coming in from outside. This would otherwise revert your flowering plant back to veg or potentially cause other issues such as hermaphroditism.




If your LED has a dimmer, now is the time to turn your light to its maximum intensity, or lower your light to the recommended distance from your plants for the flowering stage. If you are not sure what this distance is, most grow light producers have recommendations available.




Important: if you change anything with your lights, such as when you increase intensity and/or lower their position, make sure to do so gradually over several days, rather than in one go. Too sudden of a change can stress your plants too much.




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AUTOFLOWERS AND LED




If you’re growing autoflowers rather than photoperiodic strains, you don’t need to bother with initiating flowering by switching your lights to 12 hours on/off. You can just leave your autoflowers at 18–24 hours of light per day up until harvest. Then again, if your LED light has a flowering switch, you should still use it once your autoflowering cannabis is in bloom. This will help increase yield.