The light cycle for cannabis seedlings is a pretty debatable topic, and several researchers present their personnel point of view based on their findings. But, the actual growers are of different opinion when it comes to the seedling light schedule.
Generally, Cannabis plants grow in three ways: The first method deals with germinating seed indoors and allowing the Cannabis plants to complete the entire lifecycle within a controlled environment. In such an environment, the Light schedule for seedlings varies in different cannabis strains across the processes that plants complete within such an environment.
The second methods deal with completing the first two processes of the cannabis plant cycle, like seed germination and the preliminary seedling stage, indoors and then transplanting them to the garden beds. Here the transplanted cannabis seedling light cycle is at the mercy of the sun.
The growers can’t delay or shorten the seedling stage light cycle unless the cloud cover interrupts to shorten a day’s length, or a bright sunny day could add a few more minutes in marijuana seedling light. The growers don’t have control over the light cycle for seedlings in the third method.
It involves allowing the cannabis plants to complete all growing stages in the outer garden beds. However, the growers could regulate the light schedule for weed seedlings if they grow them in small nursery trays instead of seeding them directly to the garden beds.
Besides, updating cannabis growers about light schedules during variable growth stages such as seedlings, initial vegetative, Secondary vegetative, and flowering stages, etc., We will also highlight some ideal grow lights which are essential for the seedlings. But perform exceptionally well for the higher production that cannabis growers often dream of.
How Important is Light for Cannabis Seedlings?
While growing cannabis plants in a natural environment, it utilizes water and CO2 in the presence of sunlight and converts them into oxygen and glucose. Otherwise said that it is the process that converts light energy into chemical energy that cannabis plants utilize for the growth and development processes.
Several physiological processes also take place only in the presence of light. When we grow Cannabis indoors, we have control over all factors But, the light is the limiting factor that is supplemented with the help of an artificial source. As the efficacy of any light determines the THC level in cannabis plants, it becomes necessary to provide cannabis plants with the light source that excels.
We see several types of LED Grow lights on the marketplace for this purpose. We would better discuss them later. Let’s first determine: why the growth of seedlings, their development, and care are more important than all other growth stages of cannabis plants?
The cannabis seed contains both the “code” and “coat”. A seed coat encloses the food that seedlings depend on for the initial few days after germination. A code contains the inherited characteristics: that how cannabis plant would look like, it’s degree days to mature, flowering pattern, and THC level. etc.
It is important to note that only female plants’ seed reaches the buds formation stage. Male plants are not viable. But, they could achieve a similar height and shape since they belong to the same genetic code. Once the sprouts emerge from the seed and utilize food stored in the seed coat, it becomes very prevalent for the seedlings to assimilate food for their survival. This food synthesis is dependent on a quality light that helps them fix their food, instantly.
At his stage, seedlings need to be exposed to a bright source of light for prolonged hours. This duration may not be available to every grower working on cannabis seedlings, so the growers expose seedlings to the artificial lights in their growing environment. Seedlings are the foundation stone for any crop that determines their success in the rest of the stages till maturity, provided that the other conditions remain ideal in the process.
Light Schedule for Seedlings
Now, I hope that the role of artificial lighting or light supplementation is pretty much clear during the seedlings stage of cannabis growth. Seedlings have to switch from the stored food mode to self-assimilation. These seedlings would not need only the prolonged lighting hours But, the special care that, typically, a small plant needs from day one. Be sure the cannabis seedlings’ other requirements are also small due to their size.
Cannabis seedlings could survive only with little irrigation, a smaller amount of fertilizers, and other inputs. But it would want a continuous source of light to assemble their food. Coming back to seedlings’ light schedule, cannabis seedlings grow successfully, where they receive at least 14 hours of sunlight in their natural habitat.
Since indoor cannabis growers install LED grow lights because the light is the only limiting factor there. They expose cannabis seedlings for 18 hours at least and keep lights off for the next 6 hours. If any indoor grow room doesn’t receive even the ray of outdoor light during the day, it is good to keep the lights switch off during the night.
This practice could provide your cannabis plants to complete darkness for the next 6 hours after exposing them to extended hours. Seedlings or fully-developed plant uses stored energy during the night and keep on translocation energy to different parts of the plants at night.
Some growers and researchers are convinced about exposing cannabis seedlings to even longer hours. It could be 20/4 or 24/0 before the initial vegetative stage arrives. After that, they continue selecting the 18/6 schedule up to the late vegetative stage. A distance of an artificial light source is also important.
Cannabis seedlings are delicate like every other plant while keeping lights closer to the plants’ canopy could burn them. It is necessary to maintain a fair distance of the light from the seedlings. Usually, it varies between 24-36 inches which, depends on the intensity and wavelengths of LED grow lights. When cannabis plants advance to late vegetative and flowering stages, light scheduling changes and more intensive lights help flowering and budding stages.
How many hours of light for seedlings?
It is suggested to expose seedlings for 18 hours a day for the initial 14-21 days. You could continue the same routine till the start of flowering.
How much light do cannabis seedlings need?
Cannabis plants don’t like high-intensity light during the seedlings stage as it causes to burn out foliage and rapid drying occurs that may dislodge plant seedlings. Usually, placing LED grow lights 24 to 36 inches above the canopy is more beneficial for their rapid growth.
However, it entirely depends on the wattage of any light that it uses. After the seedlings develop an intensive root system, you could move to grow lights closer and reduce the lighting hours. Anyways, switching LED lights on for 18 hours is the best practice for seedlings.
Top 10 Best Marijuana Seedling Light Review 2023
#1 VIPARSPECTRA-300W LED Grow Light
VIPARSPECTRA is a reliable name in the making of LED Grow lights, while the 300W Reflector series is typically engineered to deliver full-spectrum throughout the lifecycle of marijuana. It draws hardly 129 Watts which, makes it super energy-efficient light of this capacity.
The growers could hang it between 32-36 inches above the canopy of plants for cannabis seedlings and operate for 18 hours a day since it provides an excellent steadiness in coverage and PAR output. Light hanging distance could reduce to 24 inches during the vegetative stages and 12 inches during the flowering period.
Heat dissipation was also dealt with superbly using aluminum-cooled sinks and 2-additional mute fans. They offer a 2-year warranty on the product and 1-month for returning the product if found defective. They also install Bridgelux 5W EpiLEDs that is a stable product. See customer’s reviews and rating using the above Amazon link.
#2 MARS HYDRO-TS 3000W LED Grow Light
It’s relatively the newest version from MARS HYDRO that could complement light needs for large growing spaces. It’s one of the top choices for commercial facilities with an active footprint of 25 square feet during the seedlings and vegetative growth.
It could competently replace 1000 watts HPS while drawing only 450 Watts for 1016 power-efficient LEDs. MARS HYDRO also claims 2.5-gram production per watt, which could remain a claim unless tested by some potential growers. Be sure that seedlings need a PPDF of 100 micromoles per second.
That’s the reason, MARS HYDRO installs a dimmer switch that allows the growers to regulate light according to different growing stages of cannabis plants. Overall, TS-3000 is waterproof and installed with Mean Well Drivers for dimming options. Daisy-chaining also allows you to connect 15 lights at a time, especially in commercial growing arrangements.
#3 WAKYME Full Spectrum Plant 600W LED Grow Light
Typically, WAKYME 600W is an economic light from the point of view of both costs and power consumption. WAKYME works more on the quality and safety of their grow lights than other players in the same industry.
This upgraded version adopts a 120° degree beaming angle with reflectors in place to spread the entire wavelength across the surfaces of the cannabis plants. When it comes to saving energy, the 600 Watts unit runs on only 277 Watts. Dual switches could allow you to adjust bluer wavelength while hanging this unit 18 inches above the canopy of plants.
Otherwise, it would perform excellently by switching it to a vegetative mode for the period before flowering. Product warranty and return conditions are also good.
#4 Yescom-225 Blue LEDs Grow Light
Since the Cannabis growers know that bluer is necessary for the seedlings and initial vegetative stages, this ultrathin could support seedlings’ growth in any of the growing environments, either it’s a greenhouse, grow room, or hydroponic arrangement.
It’s pretty easy to install and relocate across different growing facilities for complementary accessories like a hanging kit, snap-link, and hook. A highly Efficient light that operates on hardly 22 Watts, irrespective of a more number of LEDs (225) installed.
Moreover, a 120-degree beaming angle gives the light access to reach 18 square feet if you’re growing cannabis seedlings under it. If one or more LEDs stop working, the rest of the panel will continue to operate. Heat dissipation is excellent with a solidly built fiberglass light panel that makes it safer for the users. They offer a 3-year warranty on LEDs.
#5 Elaine-LED Grow Light for Indoor Seedlings
If you’re looking to grow a few cannabis plants indoors then this light could better complement seedlings’ requirements. It has brilliant blue and red wavelengths, and it uses 3-heads that emit a brighter light with low heat. You can use each head across 3 different cannabis stages and automate them for their running duration.
Once automated, you are worry-free to switch on or off your lights. They also install dimming options up to 5 levels, multiple switch modes, and LED chips with a lifetime warranty. Furthermore, the wavelength varies between 400 nanometers to 840 nanometers.
Its goosenecks are flexible to 360-degree with the liberty to adjust both beaming angle and distance from the surface of cannabis seedlings. Moreover, it could help you complete the entire lifecycle of three different cannabis plants if used intelligently.
#6 VeRosky-LED Grow Light 1000W, Reflector Series
This light dissipates heat better than conventional LED grow lights due to installed SMD chips and create a favorable growing environment for growing cannabis seedlings under them. Otherwise, this LED is suitable for all growing stages of cannabis plants for an increased number of LED chips.
Chip placements allow 276 chips to emit wavelengths between 380-780 nanometers, while 24 chips become capable of delivering 660 nanometers. Moreover, 90-degrees light-reflecting angle makes it a bit of professional light that often cannabis growers demand. This reflection process also increases more light penetration into the foliage and reduces light losses up to 30% or more.
Besides growing cannabis plants, this is an ideal light for all plants that bear fruit and take a long time to mature. The Growers could plan to grow vegetables such as tomatoes, cucumber, and peppers under these lights along with growing strawberries in the grow room.
#7 AOSBEIC Dimmable Full Spectrum LED Grow Lamp
AOSBEIC could help growers to grow faster with their linear optics technology that spreads light evenly over the surface of the plants. They increased light penetration into the foliage to grow them faster, compared with the conventional LED lights on the market place.
The growers could willingly install it between 12-18 inches above the canopy of cannabis plants without fearing burnout. No fans installed but, the heat dissipation is excellent. One unit of light could help growers to maintain and establish cannabis seedlings in 8 square feet, while a dimmer helps to control intensity throughout the planting period.
They offer a 8-year product warranty and return guarantee with a support center, professional guidance.
#8 Advanced Platinum Series-P150 LED Grow Light
P-150 will give you considerably large grow space to establish Cannabis seedling in 16 square feet if you hang it according to the Advanced Platinum recommendations. However, you could hang it further apart at 24 inches to increase this area to 24 square feet, which is fairly large that a grow light of this capacity could cover.
It is a highly energy-efficient light that draws only 87 Watts to deliver the highest PAR resulting in the highest yield while delivering a complete spectrum needed for the growth of seedling and then entering into the vegetative and flowering stage.
The light intensification made with the installation of secondary lenses provides Ultraviolet and Infrared wavelengths along with the optimal spectrum needed for plant growth. Vegetative and bloom switches are there to facilitate growers to regulate light according to the changing need of plants across varying stages.
Product warranty is maximum, and they outcompete all players of the industry by providing a 5-years warranty along with a 3-years return guarantee if the package receives damages or unit don’t work.
#9 iPower-300W LED Grow Light
iPower-300W exhibits the right amount of wavelength that plants need during the seedlings stage. It consumes only 135 Watts that would help you save a lot on electricity costs. It’s a type of light that you could use in multiple growing arrangements such as greenhouse, hydroponic, and conventional crops farming.
This unit remains cool due to aluminum heat sinks beside it provides plants with the much-needed wavelengths including UV and IR that promote cannabis plants’ internal defense mechanism. You could hang it 24-36 inches above the canopy of seedlings to get speedy growth in the shortest possible time.
#10 Relassy-300W LED Grow Light
Another grow light with the optimal wavelengths that cannabis seedlings need at the early stage. Relassy uses 338 LEDs that yield high PAR. The reflective cups enhance light absorption through the surface of the plants increasing yield up to 35% or more.
It highly energy-efficient light that consumes nearly 60 Watts and is ideal to hang 36 inches above the canopy for the seedlings stage. one interesting fact about this light is automated switching and it could turn itself on after scheduling it for the first day.