Germination Lighting: How to Grow Seedling with LEDs

Are you ready to start germinating your seeds for an indoor or outdoor grow? Either way, the best place to grow seedlings is indoors. We’ll explain why below, but here’s a hint: Growing seedlings is a very delicate process that requires a lot of care. 

After that, we’ll go into how much light your seedlings need, when to turn on the LED lights, the correct distance your lights should be from the seedlings, and more. 

Germination Lighting: How to Grow Seedlings with LEDs

Why Germinate Seeds Indoors?

As mentioned above, the germination and seedling growth stage is extremely delicate. 

If you want a high germination rate, you want to do your germinating in a controlled environment. Then you can see when they start busting out of their seeds. You can also control moisture levels. 

When it comes time to transplant, you will know exactly how long the root is and in which direction it’s pointing. This is crucial for ensuring that as many plants as possible survive and graduate to the vegetative stage.

Many growers will germinate their seeds in paper towel because they can monitor everything. This is just one more thing to consider to boost your survival rate. 

When Should I Start Germinating Seeds?

When to do your planting depends on a few factors. 

One is whether you will be transplanting the seedlings outdoors or indoors. If outdoors, you will need to time it so that there is no risk of frost in your area. Either that or transplant and cultivate your plants inside until it’s safe to transplant them outside. 

If your grow will be indoors, then you can start germinating any time. 

Your seeds will start germinating within one to four days. Some may even take a full week. It could be up to three weeks before they all can be transplanted. 

When Should I Transplant Seedlings?

You can transplant seedlings when the roots are somewhere between 0.6” and 1”. This gives them the best chances of maturing and producing flowers. 

Measurement is easy if you’re germinating in wet paper towel. If you use rockwool cubes and they’re small enough, then measurement is almost as easy. You’ll see the roots when they start poking out of the cubes. 

If you want to transplant to an outdoor grow, it might be a good idea to wait. The seedlings should be strong enough to withstand wind and big enough so that animals won’t trample them. You can transplant the seedlings into pots in the meantime if you go easy on the nutrients. 

The whole process will take about two or three weeks. 

Do Seeds Need Light to Germinate?

Growers Choice X TSL Horti Tech ROI-E720 LED Grow Light

In the beginning, they will need darkness rather than light. After they begin germinating, they will need light. 

When Do I Turn the LED Lights On?

After you get the beginnings of a root system, you can turn on the lights. If a seedling is ready for transplanting, then it’s ready for lights. 

Seedlings need light a lot more than they need nutrients. In fact, too many nutrients could kill them. Few or no nutrients will help them build stronger roots. 

Growers typically use an 18/6 (18 hours light) light schedule for seedlings. There are some that prefer 20 or 24 hours of light daily. When in doubt, just go with 18/6. 

How Far Away from Seedlings Should LED Lights Be?

One of the great things about LED lights is that they won’t burn your fragile seedlings. Some HID lights need to be far away from them so that they don’t fry. 

Distance may still matter with LEDs because plants will “reach out” more toward lights that are farther away. The stalks could grow so long and weak that they droop.  

The other factor that determines the ideal distance for LED lights is wattage. Seedlings need a lot less light than more mature plants. The higher the wattage, the further they should be from the seedlings. 

Typical LED lights should be two to three feet above the seedling canopy. To be safe, keep the distance at the higher end of that. Three feet will be suitable in most cases. If they start drooping, move the LEDs closer in. 

Once the seedlings have strong roots and begin sprouting leaves, they will need more intense light for photosynthesis. This is the beginning of the vegetative stage. 

The lights can be one or two feet away at that point in time, depending on the wattage. 

LED Grow Lights for the Seedling Stage

Full spectrum LED lights are the most economical in the long run. They are also cool and versatile, which are two ideal qualities for the most delicate stage of cannabis growth. 

If you want an affordable full spectrum LED option that is adjustable for all growth stages, check out the Grower's Choice X TSL Horti Tech ROI-E420. The light intensity is not only adjustable. It’s also evenly distributed. Growers Choice has a collection to choose from if this is not what you are looking for.

Grower's Choice X TSL Horti Tech ROI-E420 LED Grow Light

Learn More About the Growers Choice Collection

If you want more options at affordable prices and free shipping then look into the Horticulture Lighting Group. They offer multiple light selections for indoor grow set ups.

Learn More About the Horticulture Lighting Group Collection

Ask an Expert Grower
Do you have questions about germinating seeds? We’re not just retailers. We’re growers! Call or text us. 
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