Types of Lights to Grow Autoflowering Cannabis
- 1. Do autoflowers need strong lights?
- 2. Best types of lighting used for autoflowering cannabis
- 2. a. Cfl lights
- 2. b. Fluorescent lights
- 2. c. Hid lights
- 2. d. Led lights
- 3. Sunlight
- 4. Essential indoor grow room equipment
- 5. In conclusion
Growing cannabis is genuinely satisfying, but since there are restrictions in many places, you’re forced to go indoors. In these situations, lighting plays a major role. Thus, we present to you the types of lights for growing autoflowering cannabis in 2026.
If you’re growing cannabis, lighting is extremely important, especially when growing autoflowers.
Why? Because autoflowers have a shorter lifespan. They grow and produce buds that can be harvested in as little as 8 weeks from start to finish. With such a short span of life, you cannot afford to make major mistakes.
Adding to the dilemma of an autoflowering cannabis grower, you have just too many options out there today. CFL, HID, or LEDs? While some say that CFLs are just enough for autos, those that use LEDs will completely disagree. Obviously, LEDs are stronger than CFLs, but what’s really best for autos?
1. Do Autoflowers Need Strong Lights?
Autoflowers will grow nicely even with 12/12 lighting, so why do they even need strong lights, you ask? Yes, the question makes sense. But the point is that if you want stunning yields, you’ll have to provide more light. Plus, strong lights are a must. As long as you’re not trying to reduce costs, using weak lighting doesn’t make sense.
2. Best Types of Lighting Used for Autoflowering Cannabis
CFL Lights
Unless you’re growing in a closet, CFLs should never be your choice. However, we are including it in the list here because it’s one of the options if you choose to grow marijuana without spending too much or if you cannot find proper equipment where you live.
CFLs are available everywhere. And they are cheap to beat. You’ll need to use two different types of CFLs for the growing and flowering phases, though. For instance, if the plants are in the vegetative stage, you’ll need "cold" light CFLs, whereas CFLs emitting "warm" light will be perfect for the flowering phase.
The main drawback of using CFLs is that they are not potent enough, so you will need more than 4-6 bulbs to grow an auto from start to finish, and you may still not be satisfied with the results due to the poor lighting.
Fluorescent lights
Fluorescent lights – also referred to as T5 lights by some – are great for autoflowering plants. They aren’t very strong, but the plants grow decently as long as you provide many sets of lights. Like CFLs, you will need multiple T5s to grow something decent.
T5 lights work well for plants during the vegetative stage, seedlings, and clones, but they don’t serve the purpose during the flowering phase. For this very reason, they are not generally recommended.
HID Lights
HID lights were arguably the strongest on the market. They are sturdy, strong, and last a long time. Most HPS lights work very well for at least 20 to 24000 hours. Once the bulb stops working, you need to replace it. You can use Metal Halides during the vegetative phase; however, you’ll have to switch over to HPS lights during the flowering stage because cannabis plants produce better buds under a red/orange spectrum.
One advantage of using HIDs is that they are cheap and available almost everywhere. However, due to the amount of power they consume, you may find the electric bill a little too expensive for your taste. If budget isn’t a concern, using a combination of MH and HPS lights is the best lighting you can provide while growing autoflowering cannabis. A word of caution if you’re using HIDs, though. Since they produce lots of light, they tend to heat up quickly. Thus, you have to pay attention to the ventilation.
LED Lights
LEDs, or Light Emitting Diodes, are the best lights to grow autoflowering cannabis without a doubt. Honestly speaking, LEDs are perfect for growing any kind of marijuana.
Want to grow in the closet? You can purchase smaller LEDs that fit snugly in the closet. Have a big grow room? Get one of those swanky lights with a range of power from 300 to 2000W. Yes, you can go as far as 2000W! And, talking of power, you won't be worried about the electric bill.
The best part of using LEDs is that they don’t heat up, unlike other powerful lighting equipment. They are sturdy and last longer than 100,000 hours! Yes, you read that right! These beautiful babies last so long that you’ll not have to worry about replacing them. This also means that you’d have to replace at least 5 HPS bulbs in the amount of time taken by an LED! Imagine all the money you could save!
3. Sunlight
As you might imagine, there’s no replacement for nature. Cannabis plants have been growing in sunlight for thousands and thousands of years, so we could say that sunlight is the best type of light for cannabis and for growers, as it provides full-spectrum light with UVA and UVB rays while being 100% free. So if growers can get free light that’s much, much better than the light fixtures mentioned above, why would they grow indoors? Well, depending on where you live, climate conditions may not be the best for outdoor growing, which forces cultivators to grow indoors after the outdoor season. This takes us to the next question…
Does Cannabis Grow Better in Sunlight?
Sunlight is free, which is an enormous advantage, but cannabis plants can grow under any type of light. This means that you can get excellent results with any lighting as long as you’re providing enough light. This longstanding debate will continue forever because each grower has his own style of growing, so it all comes down to personal preference.
If you’re a beginner and want to understand the basics, it’s recommended to take advantage of the sunlight because it’s free, and once you get the hang of it, you can go ahead and invest in a good indoor setup. Just keep in mind that you don’t need to follow anyone's recommendation. Just experiment and try different products and setups until you find the right one for you.
There we go, everything there is to know about all the various lighting options for indoor cannabis grow rooms, tents, closets, balconies, and even ones to use to add additional light to a greenhouse and other outdoor weed growing situations. But what about all the other equipment needed to grow top-shelf, dank-as-hell cheeba? Let's dive in...
4. Essential Indoor Grow Room Equipment
Ok, so we have all the info we could ever need on the lighting. Let's look at all the other pieces of kit you'll need to set up a successful indoor grow.
A Grow Area
Unless you are growing in a closet or small tent, you'll need some kind of grow room to keep your plants contained and secure. This is the point where many growers mess up and fail to understand the importance of air circulation, humidity control, and temperature control. Without these basic requirements, your plants will not thrive and may even suffer serious harm due to improper airflow and temperature. We almost always suggest just splashing out on a good grow tent; it will make your life that much easier in the long run
Airflow and Air Exchange
Getting ventilation and air exchange right is something you don't want to mess up. While this is an often overlooked area for novice growers, it's just as important as providing the correct light spectrum and penetration. You'll need an extraction fan that takes the hot and moist air out of the grow room and sends it outside.
Intake fans are less important for small home setups (although they are needed once you start to plan bigger grow areas), as the exhaust fan will automatically pull fresh air in. Without this setup, your plants will soon suffer due to stagnant air, lack of CO2, and the build-up of toxic substances.
It's also important to set up a few small oscillating fans that point at the canopy, in different directions, to ensure proper canopy airflow. Then there's the carbon filter. These are imperative, not just to scrub the smell of those dank buds from the air leaving the grow room, but also to clean the air inside. Carbon filters contain a specific type of activated carbon that adsorbs odors, molds, bacteria, and more.
Environmental Control and Monitoring
Getting the temperature and humidity levels in the correct zone is essential for cannabis plants to thrive. Too much, or too little of either can be damaging and will stunt growth.
The environmental conditions should be 21 - 29°C and 70- 80% relative humidity during the vegetative stage, and 15-24°C and 40-50% relative humidity during the flowering stage.
So to ensure these levels are maintained, you'll need a thermometer and hygrometer to monitor the environment. You may need an AC unit, a space heater, a dehumidifier, or a humidifier to help control the climate.
Other Pieces of Equipment
Then there are all the random things that every indoor grower should have at hand:
- An EC or TDS meter to measure the nutrient levels
- A pH meter
- Buckets
- Timers
- Nets and trellis
- A watering can
- Pruning shears
- Trays
- Spray bottle
- Cleaning equipment
5. In Conclusion
In conclusion, after comparing most types of lighting you can use to grow autoflowering cannabis in particular, you can safely say that LEDs are best. Due to the features, power, and lifespan it offers, you can be sure to grow some big buds oozing with a lot of resin.
Having said that, LED light fixtures can be quite expensive for the average home grower, but don’t worry. You can, without a doubt, get the same quality, or even better than with LED lights, as long as you provide your plants the right light spectrum and light intensity at the right time.
FAQ
Both blue and red wavelengths play important roles in plant development. Blue light contributes to vegetative growth and plant structure, while red light supports photosynthesis and influences flowering responses. However, wide- or full-spectrum lighting is recommended as it combines multiple wavelengths to support healthy development throughout the plant's lifecycle.
Blue-rich lighting can support compact vegetative development and normal leaf formation in young plants. However, for optimal results, you need to switch to a red spectrum during flowering.
Red light is an important component of photosynthetically active radiation and contributes to plant growth and flowering-related responses. However, red light alone does not guarantee healthy flowering. Overall light intensity, spectrum, genetics, and environmental conditions all influence plant development.
Insufficient lighting can lead to elongated stems, weak growth, smaller leaves, and reduced photosynthetic activity. Plants may stretch toward the available light source, resulting in less compact development.
Modern, high-quality LED grow lights are generally among the most energy-efficient options. Their efficiency is often measured in micromoles of photosynthetic photons per joule (µmol/J). A higher value indicates that a fixture produces more photosynthetically useful light for each unit of electricity consumed.
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