Can seedlings get too much light?

Posted on 31 May 2021

Can seedlings get too much light?
Can seedlings get too much light? Yes. 
Can grow lights be too bright? Yep, if it's too close!

A recent lesson learned: This is a photo from a couple weeks back, we got a new 100W Sansi LED floodlight and thought, "Wow, this super bright light is going to really get those peppers growing big before putting out in the garden!"


Well, not so fast. After a week under this bright light, we noticed that the leaves of our peppers were starting to turn purple and curl, and their growth just stopped. Too bright! I think this light would be perfect if a couple feet away, it's super bright!! But, if it's only 8" away, it's too much. We turned the light away but the damage was done. 

Pepper Seedling under too Bright a LED Light

We also think that this LED light would be great for more mature peppers with more leaves that can tolerate brighter light (or if farther away from the plants), but these baby seedlings were shocked. Light intensity can cause severe damage to your seedlings to the point where they die or are stunted. This 100W LED light was just too close to the seedlings, causing them to get burned and turn purple and suffer, they can get burned just like we do in the bright sun!


It is true that your seedlings need bright light to grow healthy and strong—but, too bright a LED light could actually damage them if it's too close – plus, seedlings also need a period of darkness in order to thrive. Generally, pepper seedlings should receive roughly 12 to 16 hours of light a day. So turn off the lights and let them sleep!  And, don't do what we did this year  and burn  them by putting your extra bright LED lights too close. Brighter isn't always better!

Seedlings that had too bright of light - the LED light was too close

These poor burned seedlings above are still recovering outside now weeks later, and they still aren't looking too happy with us! No real new growth, and their leaves are still curled and purple. Hope they recover, but if not, that's ok, we started lots of other seedlings so we'll make do! But we still feel awful for nuking these little guys. 


Harden Off Seedlings

Another Seedling Tip Regarding Light:
Make sure to harden off your seedlings!

Hardening off seedlings means introducing your indoor-grown seedlings to the sun gradually over several days to get them acclimated. If you transplant seedlings directly into the garden after growing indoors, they are not used to the harsh rays of the sun and the strong breezes, so they could have transplant shock. It is good to bring them outside in dappled shade for a few hours the first day, then bring indoors, and over the next few days bring them outside and leave them in the sun for a little longer each day, and leave outside overnight for a night or two before transplanting into the garden or containers.



Have you learned any new things this year?

Remember, there are no mistakes in gardening, only experiments!
😉



Happy growing!

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