15864 members
Login

How To Flower Cannabis Plants With LED Grow Lights

Many people contend that LED hydroponic grow lights work well during the vegetative stage but not when it comes to flowering. This misconception will become a self fulfilling prophecy if you do not know how to use the technology. Follow these cannabis flowering tips to have a successful grow.

By Ethan Grow

The first thing to remember is that when you are growing indoors, your plants do not have environmental feedback telling them which season it is and what they are supposed to do. You have to tell your plants what season it is and the way to do it is with your lighting. In an outdoor setting, cannabis plants flower in the fall when days become shorter, the sun is lower in the sky and plants are signaled that the annual life cycle is coming to an end. After about 8 weeks of vegetative growth you have to mimic this change in the day cycle. Your light schedule should be changed from 18 hours light to 12 hours light and 12 hours dark. Along with the change in the amount of time the light is on, you must also change the amount of red wavelengths the plants get. This is very easy to do with LED grow lights. All you need to do is add a LED with a high ratio of red wavelengths or all red wavelengths.

Some indoor hydroponic LED grow lights have been designed to work for both vegetative stage and flowering. These LED grow lamps will give you maximum intensity during your entire grow season. The trick is to ADD more red wavelengths when it is time to flower. Doing so will help the plant think that it is autumn and the sun is lower in the sky with more red hues. This will kick off the coveted flowering stage! A 90 Watt All Red UFO light is an ideal and inexpensive choice for getting the added red wavelengths needed. You should add one of these All Red LEDs to each light setup you have. Within a couple days of adding the UFO, you will see your plants go through another growth spurt and start the flowering process.

Another option is to switch from a Veg + Flower light to a BLOOM only light which will have a higher ratio of red vs. blue wavelengths. If this is your preferred method, you will get the most grow area coverage by having a vegging station and a flowering station, each with a designated grow light.

There are also LEDs which have a switch where you can switch on and off the blues and reds. With these grow lights you turn on half the (blue) diodes for vegetative stage and then turn on the red diodes in addition to the blue when you get to flowering. Although this method works, the drawback is that you are growing with half the intensity of the light and hence can grow less than if you had the entire intensity of all the diodes. An All Red LED grow light is always the ideal growlight to add when it is time to flower. However, you can also add HPS or CFL white lights which will have the red wavelengths.

Once you have helped your plants to start flowering, you can maximize your yield by understanding the growth process. During the flowering phase leaf growth slows and flowers start to form after one to three weeks. Fuzzy, white hairs called pistils start to grow. The pistils are attached to the light green pods called calyxes. The calyxes, full of the hair like pistils form dense clusters of buds along the stems of the plant. The buds will continue to swell and produce a resin like material called trichomes in the first four to five weeks of flowering, after which they grow at a slower rate.

The trichome resin glands are in the early stages of formation

Trichomes are milky white & amber and ready to be harvested

Trichomes are granular and are comprised of a stalk with a resin head bulb. It is the trichomes that we seek and we must let them flourish before harvesting. When the trichome resin glands are in the early stages of formation they will be clear. You should harvest when the trichomes start to turn milky white to amber for the most potent THC. This should happen around the sixth week of flowering but depending on the strain of plant you are growing, it could take more time. Once your trichomes have turned milky white to an amber red color, it is time to harvest your plants! Let the plants hang to dry for 3-4 days in a dark room to avoid change of color from light. Follow these tips and you will have successful grows with your LED grow lights!

More to read in Growing
false