Veg or Bloom Light for Autoflower

Veg or Bloom Light for Autoflower: Which Spectrum to Go For?

Depending on their growth stages, plants require either veg or bloom light. And in some cases, both light spectrum is necessary for the plant. 

But which one should you consider on veg or bloom light for autoflower?

You need to use veg light during the vegetation stage of autoflower plants. This stage might stay 4-5 weeks long on average while continuing this light setup. And during the flowering stage, you need bloom light more. However, using both light spectrums on autoflower plants is ideal at this stage.

We will take you through an in-depth discussion now. You will understand the lighting differences between these two clearly. 

So, let’s get going!

Veg or Bloom Light for Autoflower: Table Comparison

Each light spectrum has its own characteristics and impacts the growth of the plant differently. 


Before going there for in-depth discussions, we’re going to compare veg light with bloom light:

Comparing FactorsVeg LightBloom Light
GrowthHelps growing stems and leavesRare cases to grow anything
SuitabilitySpecialized for vegetative phaseSpecialized for blooming phase
Light Spectrum6500K2700K
Lighting Schedule(per day)18/612/12

That’s pretty much the basic difference between the two light spectrums. On the visible spectrum range, the veg light falls from 400-500nm and bloom light falls from 620-780nm.


Veg or Bloom Light for Autoflower: Detailed Comparison

Enough of scratching the top of the iceberg! Now, it’s time to see the details between these two. It will lead you to compare and understand better. So, let’s dive in! 


A vegetative or veg light comes as an artificial grow light into the picture. More specifically, it manipulates the growth of plants during the vegetative stage. 

You might find different versions, technologies, capacities, light outcomes, etc., of veg lights.

The auto-flowering process usually involves the modification of a plant’s growth into the flower blooming state. To do that, you might need to change the light spectrum. That’s where the bloom light comes in! 

It brings a redder spectrum that helps plants to bloom during the flowering step. So, changing the Photosynthetic Active Radiation or PAR lighting spectrum is vital to bloom.


Growth in the vegetative stage highly represents stems and leaves growth. Meanwhile, you will not see flowers beginning to bloom here. 

Rather, this step deals with the shapes and sizes of plants. That’s why light is more important to focus on. 

The more veg light you apply, the more growth of your plant will be visible. Blue light during flowering doesn’t do much in helping the plants to flower. 

You might be wondering:

Is blue light good for plants?

Yes, during the vegetative stage of a plant, blue lights help to make the plants bushy. Also, the blue light helps the plant grow greener leaves and stocky roots.

Meanwhile, red or blooming light facilitates flowering. Are you expecting more from your plants than vegetation? Then, it might require a red light to go further. 

Consequently, instead of having vegetation, you will find it serving you flowers from the plants. If we consider auto-flowering a 10-week process, then the bloom state starts in the middle. 

In the 5th or 6th week flowering small buds will be visible. Along with that, it promotes the multi-level growth of your plant. However, balancing the lighting is crucial.

If not, there are so many cases involving stretch issues of plants. As a result, you might face more inferior yields along with lean, unstable plants.

You should also be careful about the ph level of the soil. For that, you can use the market-leading Kensizer soil tester to test the soil ph regularly.

Better Spectrum

Usually, the combination of LED grow light serves the best result. However, plant growth depends on a particular light spectrum at different stages. 

As a result, one light might have the best impact between the veg and bloom lighting. How should you figure out that? Well, several kinds of research found out that the range from 3000K to 4000K is ideal. 

Relevantly, this impact helps plants to have healthy growth and the highest gain. Meanwhile, veg light comes with 6500K of the light spectrum. On the other hand, 2700K is the average temperature of bloom light. 


So, the bloom light lies closer to the ideal range. We might consider the bloom light as more efficient compared to the veg light indeed.

Light Schedule

The vegetation stage of a plant requires a high amount of lighting. Meaning that a plant requires the majority of the day under lighting. A plant highly demands an 18/6 lighting schedule to proceed.

As a result, 18 hours a day is an average lighting period. Without applying this schedule, the expected plant growth won’t happen. 

Along with that, the overall vegetative phase will be delayed. Many growers claim darkness is not required here. But you need to turn off the light for at least 6 hours.

Bloom light is mainly used during the flowering stage. The flowering or blooming stage demands a 12/12 schedule. Increased darkness helps the plant to facilitate its flowering.

If you want your plants to flower, you have to make sure that your plant receives at least 12 hours of darkness. Around this time, you should also use pruning shears and other essential gardening tools to clone the plants.

As a result, switching your artificial light such as LED Grow light into the bloom mode is mandatory. 

Final Verdict: Veg Or Bloom- Which LED Light You Should Pick?

Generally, LED lights come with several switches so that shifting to a particular color is possible. However, in terms of planting and seeding, you require a reddish and bluish variant as a dominating factor. 

While the autoflower process requires going through a vegetating stage, you might need to veg switch on. However, after approximately 3-4 weeks, the bloom stage starts happening.

It’s advisable to shift into a bloom switch for that. Meanwhile, it also carries the sign of pre-flowering.

The best thing about a full-spectrum LED light is that you get a lot of freedom with it. Depending on the height and number of plants, you can easily tune the light spectrum. 

Not only that, but you can also have both the light spectrum on at the same time to provide more lighting. 

And just because of this, every grow gardener should use LED grow lights for their plants. To help you find the best deals, we’re here with some great LED grow light recommendations! Take a look at some quality 1000 watt LED grow lights:

The reason we chose these LEDs is that they are well-reviewed and received in the grow gardening community. 

Many grow gardeners have stated that they are well content with the output of the grow lights. You should also grab them if you’re thinking of taking grow gardening seriously!

Meanwhile, you must know blue and red light represents the suitability of the vegetative and blooming stage respectively. 

More specifically, it’s good to implement 6500K and 2700K of veg and bloom light respectively. However, you might schedule them into different measurements. 

But mostly, plants grow faster without any issues while you set lights in this manner.

In summary, veg and bloom LED lights- each light spectrum has a different effect on plant growth.

However, a blue or veg switch is a must-starter from the beginning. And, it might need to stay until the pre-blooming part comes into the picture. 

Then, you might look to switch both switches on for the rest of the part. 

Winner: Both lights have a particular role in the autoflowering process. So, keeping these both is advisable.


Do Autoflowers Need Complete Darkness?

You don’t necessarily require a dark cycle to grow autoflowers. However, many growers believe in dark period competency. 18/6 schedule can preserve more electricity. Relevantly, 24/0 decreases humidity while increasing temperature, and the light bill. So, both are win-win situations for growers.

Where Should I Mount the LED Grow Lights?

Mounting LED grow lights at least 24 to 36 inches above your autoflower plant is ideal. However, keeping them a bit closer in the vegetative stage is advisable. It can be within 12 to 24 inches above. Meanwhile, demand for light decreases in the bloom stage. So, 18-24 inches would be perfect there.

How Can I Maximize Yields in Autoflowers?

To maximize yields in autoflower, you should maintain optimal ph and nutrient strength for your plants. Meanwhile, you should pick containers that can drain perfectly. Along with that, don’t forget to check out the pH level. Using proper training techniques and light cycles also helps.

Final Word

Now, you know better whether veg or bloom light for autoflower is suitable or not! 

Be careful about providing adequate veg and bloom lighting during the respective stages of growth. Also, make sure that the plants get enough time in darkness once it reaches their bloom stage.

Happy planting!

Leave a Comment

Your email address will not be published. Required fields are marked *