Best Grow Lights in 2020 for Seedlings, Veg Phase & Mother Plants
One common theme I’ve noticed among indoor growers is that many use separate grow areas for different stages of growth. That includes using one grow light specifically for the seedling and vegetative (veg) growth phases, which includes mother plants.
Keep reading below to determine which one may best suit your specific needs.
What are the best grow lights for cannabis seedlings, vegetative phase and mother plants?
Speaking honestly, any grow light with a white 4000K or 3500K spectrum will get you through the seedling and vegetative phases of growth. I don’t recommend 3000K for seedlings or veg because this color temperature is heavy on red wavelengths which is better for flowering.
If you want a dedicated seedling, vegetative phase, or mother plant grow light, the models I list below would be very good choices based on their specifications.
The best grow lights for cannabis seedlings and the vegetative growth phase are the HLG 300L B-Spec, the California Lightworks SolarSystem 275 Veg Master, and the Optic 300 VEG. These are all LED grow lights that are heavy on blue spectrum, specifically designed for the vegetative phase.
Another situation where you’d want one of these heavy blue spectrum grow lights is if you’re maintaining a mother plant. A mother plant is a cannabis (or other fruit/vegetable yielding) plant that you want to save for the sake of preserving its genetic makeup and creating clones.
The HLG 300L B-Spec may look small, perhaps for a 2×4 foot grow area. But the LEDs on the HLG 300L B-Spec are actually strong enough to grow seedlings and mother plants in a 4×4 foot area.
The B-Spec version of the HLG 300L model pictured above has a spectrum and LEDs specially geared towards plant growth in the vegetative phase. In other words this is a full blue/white spectrum grow light for seedlings and mother plants.
Take a look at the HLG 300L B-Spec spectrum below:
This seedling grow light utilizes Samsung’s LM301H 3500K white spectrum, plus 470nm blue LEDs. Out of all the LED grow lights I’ve seen, the HLG 300L B-Spec is the most dedicated seedling and veg spectrum available.
The HLG 300L B-Spec pulls 270 watts from your outlet when running at full capacity. If you desire, you can dim it down to 90 watts, or 33% power.
Larger Model for Larger Spaces:
Need to light an even larger grow space? Consider the larger HLG 550 B-Spec which has the same spectrum, but covers 6×6 feet.
Sure there are small grow light bulbs and tubes available for seedlings and veg phase as well (click here if you want to see those), but the light strength & spectrum quality doesn’t compare in a head to head comparison.
In addition, you’ll need several of those units to cover the 4×4 foot space you get from the HLG 300L B-Spec.
This is the California Lightworks SolarSystem 275 Veg Master. This light has a fully customizable spectrum, allowing it to emit heavy blue spectrum if desired.
The light has internet gateway and smartphone control options to make programming and timing a breeze. The light is built with top-bin Osram diodes, draws 200 watts from the wall, and will cover a 5x5ft veg space.
The PPFD is about 440 uMol at the highest point. At 2.2 uMol/joule this light is using electricity quite effectively. Most high end grow lights are over 2.0 uMol/joule.
The operating temperature for the light is up to 107 degrees, and it has a very large cooling fan attached to the top side of the panel. California Lightworks offers a 5 year warranty on this light.
Click here to see more details and pricing for the California Lightworks SolarSystem 275 Veg Master at LED Grow Lights Depot
This is the Optic 300 VEG by the reputable Optic LED grow light company. This dimmable light is a dedicated Veg/Clone/Mother light. The cool 5000K or 6500K white light temperature is ideal for maintaining vegetative growth. You’ll get a 4x4ft coverage hanging this light at 18 inches – perfect to light a nice veg room.
The 120 degree lenses are intended to help spread light evenly across your canopy. The Optic 300 VEG is passively cooled with an overbuilt aluminum heat sink, no fan required. The light pulls 300w from the wall when operating at full power. You can dim the drivers in 25% increments by turning the large knob next to the power button.
From looking at the spectrum chart you can see it has a high amount of blue, some green, and not much red. This light spectrum was specifically designed for vegetative growth. Let’s take a look at the light intensity:
These are very solid light intensity (PPFD) readings for plants in the vegetative growth phase. You can probably hang this light even a little higher than the recommended 15″ and get very solid results.
This light comes with a 10 year warranty! Longest grow light warranty I’ve seen anywhere!
|Optic 300 VEG grow light:|
|LED Brand:||Samsung LM301B & CREE Xlamp CXB2540 COBs|
|Drivers:||Mean Well HLG 150|
|Dimensions:||36″ x 9″ x 1.25″|
|Efficiency:||2.4 uMol/Joule (high)|
|Where to buy:|
Why I advise against tube grow lights (T5/T8) for seedlings and mother plants:
When comparing to LEDs, the spectrum is not as complete, and the light intensity is sub-par. When you read about light intensity required during the seedling and vegetative phase of growth, and then look at how strong the tube grow lights are, they seem a bit weak and probably don’t give the best possible results.
What is the vegetative phase (veg)?
The vegetative phase (often called “veg”), is the phase of plant growth between seedling and flowering. This is when the plant forms, and your grow light and light spectrum play a crucial role in the plant’s development during this phase.
It’s this phase that the plant develops roots, stem and node spacing,
Most growers prefer their plants to be short and bushy, and the best way to ensure that is by providing your plants enough of the essential blue spectrum they require during the vegetative phase.
Why blue light spectrum is best for the seedling and vegetative growth phase, or maintaining mother cannabis plants:
If you haven’t figured out from reading yet, the blue light spectrum is the best for several plant developments like chlorophyll and chloroplast development, enzyme synthesis, and plant density. It also regulates responses to biotic environmental stresses.¹
Blue light and UV-A wavelengths also trigger cryptochrome and phototropin, which regulate chloroplast relocation, germination, elongation, and stomatal opening, which impacts water transpiration and CO2 exchange.²
In short, the formation of your plant and it’s ability to carry out certain functions in the flowering phase are directly affected by the quality of life it gets in the vegetative phase.
Why pick these grow lights for veg compared to other grow lights for both phases of growth?
When you compare a dedicated veg grow light to a multi-phase grow light, you’ll find that not surprisingly, the multi-phase light has less blue light intensity. That’s because those lights need room for LEDs that emit both blue, and red, and sometimes more.
If you’re looking to grow the best harvest possible, in addition to other factors, I strongly suggest considering a dedicated veg light. If you’re looking for a grow light for your mother plant, you’ll only need one with a blue spectrum, in which case a dedicated blue spectrum light would also be appropriate.
Why do growers want grow lights specifically for the seedling and vegetative phase (veg)?
Growers may decide to buy a dedicated grow light for the seedling and vegetative phases if their current grow light doesn’t emit enough blue spectrum – the spectrum that’s critical to the vegetative phase.
If you’re maintaining a mother plant you’ll only need a blue spectrum, and you’ll need a light that’s emits a blue spectrum that’s intense enough for a full sized mother plant. Having a light dedicated for this purpose is a smart choice.
The different aspect of the seedling and vegetative growth phases that requires an adjusted growing method are these two simple factors:
- The different light wavelength absorbed in this phase (we already discussed that)
- The increased sensitivity to light during these growth phases – which requires hanging your grow light higher than you would during flowering phase. This is why many of these seedling & vegetative phase grow lights emit lower PPFD readings. It’s because if you put too much PPFD on plants in these growth phases, you’ll risk burning them.
How Far Should Seedlings and Veg Phase Plants Be From Grow Lights?
Generally speaking, grow light manufacturers recommend hanging your grow light 24-30 inches above seedlings. But every grow light is different, so I advise reading my grow light hang height article, and following the steps for yourself to determine exactly how strong your grow light is, and how high you should hang it.
For the Vegetative growth phase you can get a bit closer, so hanging your grow light 18-24 inches from the canopy is more appropriate for this growth phase.
In reality it’s not the height that matters, you’re simply adjusting the intensity of light on your canopy by raising or lowering your light. So the logical solution to fix your problem is to determine the grow light height where your plants receive the ideal amount of light intensity for that phase of growth: 200-250 micromoles for seedlings and 300 to 400 micromoles of PPFD for vegetative phase plants.
I tend to say grow light hanging height is not a perfect science. You may find your plants react better if your lights are a few inches closer or further than manufacturers’ recommendations. The good news is if you find your plants start to get burned leaves from being too close, it’s a totally recoverable event, unless you let it go on too long. So check up on them regularly when you’re just starting out.
What’s the best grow light for a mother plant?
The best grow light for a mother plant has a strong blue spectrum with a coverage area large enough for the whole plant.
What light spectrum is best for the vegetative phase?
Blue spectrum is absorbed by plants during the vegetative phase and used to develop the plant’s structure, and prepare it for flowering.
What height to hang grow lights for seedlings?
Most grow light manufacturers recommend 24-30 inches for seedlings.
What height to hang grow lights during the vegetative phase?
For the grow lights mentioned above, 18 inches. In terms of intensity, you’d want a level where light intensity is 300-400 uMols.
What’s the best grow light for a very large vegetative grow space?
The Scynce LED Raging Kush will cover a 5 by 5 foot grow space for the vegetative phase with its fully customizable spectrum.
Is a grow light with majority blue spectrum only good for the vegetative phase?
Yes. You need balanced blue and red light for the flowering phase.
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- Goins, G.D. et al. “Photomorphogenesis, Photosynthesis, And Seed Yield Of Wheat Plants Grown Under Red Light-Emitting Diodes (Leds) With And Without Supplemental Blue Lighting”. Journal Of Experimental Botany, vol 48, no. 7, 1997, pp. 1407-1413. Oxford University Press (OUP), doi:10.1093/jxb/48.7.1407. Accessed 7 June 2019.
- Schwartz, A. & Zeiger, E. Planta (1984) 161: 129. https://doi.org/10.1007/BF00395472
- Eichhorn Bilodeau, Samuel et al. “An Update On Plant Photobiology And Implications For Cannabis Production”. Frontiers In Plant Science, vol 10, 2019. Frontiers Media SA, doi:10.3389/fpls.2019.00296. Accessed 7 June 2019.