When to Put Seedlings Under LED Light? Know Now!

To grow plants indoors successfully, you must have good knowledge about what seedlings want. Growing plants indoors is not a simple task as someone might think. It requires precision and knowledge to grow the plants in the best possible shape and quality. It is no secret that in plants’ whole life, a seedling is the most sensitive stage. Thus, extra care should be done in this stage of growth. One care is to know When to Put Seedlings Under LED light.

Moreover, we are also addressing many other questions related to seedlings growing under led lights. So, stay with us till the end because if you miss this article, your seedlings may pay the price.

When to Put Seedlings Under LED?

You must be wondering when do I put my seedlings under light, Well this section will answer your question. After sowing seeds, the first thing a grower has to deal with is seedling.

To get out from the state of confusion, People search, can you put seedlings under led light or some other regular lights will also do the job. Well, let us tell you there isn’t a light that is as effective as LED. But When to put seedlings under LED lights? Moreover, Is there any precaution you should take while using LED?

Seedlings should be put under the led right from the start when they emerge from the soil. You should never delay this as depriving the seedlings of light may lead to poor growth.

This led light is not for remuneration purposes. It does the exact same role that sunlight does outdoors. Plants do photosynthesis when this led light falls on them.

We all know that how important is the photosynthesis process for plants. Imagine you don’t get to eat food one day or for several days. You will surely become weak and death may occur as well. Similarly, food is important for seedlings too which they produce via Photosynthesis. This is why experts recommend putting seedlings right away under the led.

When to Put Seedlings Under LED
Light falling on the Seedlings

Sometimes it is hard to answer when to put germinated seeds under Light. It depends on the plant’s nature too. If the plant is sensitive like cannabis, then the answer to when to put seedlings under grow lights question changes.

When do I put my weed seedlings under light?

Want to know when to put Autoflower under lights, then this part is for you. As Cannabis seedling is highly sensitive, putting them under a strong LED light will cause a light burn. That is why if you are growing cannabis, first use CFL bulbs with blue lights. So, When to Put Seedlings Under LED to get top quality Weed plant?

When the true leaves start to form, you can switch to LED lights. But this may take up to two weeks and you have to keep the seedling under a CFL bulb till then. So, whenever someone asks when to put weed seedlings under light, we suggest you answer them that first use CFL bulbs and after 14 days, use LED.

What should be the distance between LED lights and seedlings?

After knowing about when to put seedlings under light, you should also know about the distance between the seedling and the lighting source. It is necessary to put the led lights at the optimal distance to seedlings. The position of led lights determines the effectiveness of this whole lighting. So, What should be the distance between LED lights and seedlings?

Well, Lights should neither be too far to reach the seedlings properly, nor they should be too close to cause a light burn.

When to Put Seedlings Under LED
Seedlings growing under a Solar-powered LED bulb

Here’s a table to better know about the whole distance situation.

210W 15-30 inches
450W20-30 inches
600W24-26 inches
900W26-40 inches

You can see the answer to your question about when to put seedlings under 600w led in this table.

If the growing light is HID, then follow the following recommendation:

400W 13-20 inches
600W15-25 inches
1000W20-30 inches

You can also use fluorescent light for seedlings. Hang them 15 inches above the seedlings for better growth.

When to put seedlings under 600W LED light?

Since 600W light is famous, so hundreds of growers search daily when to put seedlings under 600w led light? Well, if the plant you are growing is not sensitive, then you can start using 600W very soon. If the plant you are growing is sensitive, then let it grow a little more.

It is advised that hand 600W led light after 14 days of germination. However, the led distance between the led and seedling must be optimal. If you are growing both insensitive or sensitive plants, the distance between the seedling and the 600 W led light should be 24-26 inches.

People ask this question most often, “Do seedlings need light 24/7?” The answer is No, you should not give light to seedlings 24/7. That will cause problems that may go beyond repair.

So, how long seedling should be put under the led lights? According to experts, give 14-16 hours of lighting and then let the seedlings rest. Just like a human needs to relax, seedlings and led need to relax too. So, give them time off in the night.

Should you rotate plants under the Led Lights?

If you know about your stuff like when do I put my seedlings under led light, then it is time to know about rotation.

If all the seedlings are given proper lights, then there is no need to rotate them. However, many times the situation arises when the tray is bigger than the area lights are covering. In this situation, seedlings at the edges of the tray do not receive light. Thus, it is better to rotate seedlings in this condition so that every seedling receives light.

When to Put Seedlings Under LED
Plant growing indoors

Another question pops into a grower’s mind which is, Can you grow seedlings without any artificial Lights (E.g, Led lights)?

Yes, you can grow seedlings without any artificial lights if the growing room has a window and enough sunlight passes through and falls on the seedlings. But most of the rooms do not have this luxury, that is why led lights installation is a must.

Both red and blue light are emitted from the led grow lights, but which one is better?

Red or Blue light for Seedlings: Which is Best?

You might be wondering What color light is best for seedlings? Although both are light colors, red and blue colors have different impacts on plants. Red lights promote flowering growth and fruit production. On the other hand, Blue light is hung for those plants which you are growing for foliage as this light promotes vegetative growth.

So, which light should be used for seedlings? Well, let us tell you that you should always have the best of best worlds. That is why always use full spectrum led grow lights for seedlings. In this light, you get both red and blue colors in different ratios.

Best Cheap grow light for seedlings

Are you wondering which grow light you should buy? Then here are a few suggestions from us which you may want to consider.

Spider Farmer Grow Light

Spider Farmer Newest SF-1000 LED Grow Light is one of the famous grow lights available in the market.

Key Features:

  • It has a 300-W Bulb
  • It is a full spectrum light (Blue to red light ratio is 8:1)
  • Two-year warranty
  • Has an in-built cooling system
  • Durable


Jueyingbaili Full-Spectrum light is another grow light you can install and hang above your seedlings. It is a full spectrum led light in which red and blue light are in a 2:1 ratio.

Key features:

  • It is adjustable
  • Timer is attached
  • Easy to install


VivoSun is the third grow light we are recommending. There is a reason why we have picked this grow light. Know the reason by looking at the features!

Key features:

  • Equally effective for any type of plant.
  • Durable
  • Easy to install
  • Customer service is good

Final Thoughts

All in all, growing plants indoors requires special care and attention. One important aspect of indoor gardening is how a grower is using LED grow lights. After sowing seeds and observing germination, people always wonder When to Put Seedlings Under LED lights. In this article, we answered that you should always put the seedlings under the light as soon as they emerge from the seed. There should not be any delay as this may lead to a disappointing yield.

Moreover, go for such lights that have both red and blue spectrums. Only these types of lights are best for plants to help them achieve their full potential. Do what we are recommending and enjoy successful gardening!

If you still want to know more about seedling’s light requirement, here is an FAQs section to further address your confusion.

FAQs about When to Put Seedlings Under LED

Can I put seedlings under LED lights?

People search can you put seedlings under led and Yes, you must put seedlings under the LED lights if you are growing them indoors. We all know that light is super important as it is necessary for the production of plant food (Glucose). Plants cannot experience vegetative and reproductive growth without photosynthesis. Different parts of plants utilize the glucose made from photosynthesis to grow quickly.

Moreover, be careful about when you choose to add lights over the seedlings. People ask about when to put light on germinated seeds, and the answer is when you see seedlings emerge, then straight away give them light. If you follow this guideline, then you will witness early successful growth.

Should seedlings get 24 hours of LED light?

People search Can you put seedlings under LED 24/7 and the answer is No, seedlings should never get light 24/7. Like any other living creature, Seedlings must also rest. Give them 14-16 hours of light (This is how many seedlings growing outside get).

Giving them light non-stop will cause many complications. Imagine you eat excessively without stopping. You will end up in pain and plants are no different too. If you give light 24/7, then more photosynthesis will happen and excess food will damage plants. Moreover, the chances of the light burning are also more if light falls on plants without any break.

How many hours of LED light do seedlings need?

According to the experts, the seedling should get 14-16 hours of light in a day. This time range is normal and this is how much seedling gets sunlight if grown outside.

How far should LED be from seedlings?

It must be not too close to seedlings as this may cause a Light burn. It must also be not far away from seedlings where plants don’t receive light with the required intensity.

There is a test people do to know the exact location called the Hand test. In this, you put a hand on top of the plant and feel the heat coming from the lamp. If your hand gets too hot, then put the lamp away further. Do this until your hand doesn’t get heated quickly. However, this is not a reliable method.

Plus, we have also added a table about the distance between seedling and growing lights. This distance is recommended by experts after thorough research on this subject.

Related Topics:

I am a graduate in Agriculture Sciences and have been doing gardening for over 7 years. I am also a professional and certified Article & Blog Writer. I am happy to share my years of experience in gardening with all of you through my writings. In addition to this, I do extensive research on every topic to enrich readers with valuable knowledge.