Can LED lights burn leaves?

[IngieBee]

Agreed, I moved the lights up as high as they will go (an additional 6"+ ) and have moved it to the side. I am hoping it's enough! (fingers crossed )

There must be hot spots on my shelf, because what I thought was the same amount of light, hasn't done any coloration to my miltoniopsis or Aliceara or other oncidiums, but they are smaller and may have had shade :P

[IngieBee]

RE: my original question, can these blurple LED lights burn, I found out that yes, but the leaf has to be actually touching the bulb, LOL. One of my catasetums grew so tall, so fast, it was laying on top of the unenclosed (exposed LED) lights, about 1/2cm away due to the cone the LED sits in. And they got spot burns. I moved the plant of course, and I don't know how long it took before I noticed but it seems the lights will burn under extreme close contact

[Ray]

Plants don't have to be in contact with heat in order to burn. Excessive photons flux can do it.

The simple rule of thumbs about artificial lighting is that the continual light intensity should be about 1/2 of the peak light intensity given in guides for the plant.

[IngieBee]

Thank you Ray. Unfortunately information is really lacking on these cheap LEDs (and cheap is the reason for getting them, LOL. Even then, when I get my greenhouse built, I'll have to start all over again, checking to see which plants are happiest where with how much sunlight. Generally here, it's a lot less than what people say. "Full sun" here means partial shade, LOL.

I was really just posting because I thought it was funny the way the leaves burned. I ought to share a picture

Catasetum leaf burn by ingiebee, on Flickr

I'm sure my Catasetum didn't see the humor in it.

I know my dendrobium nobele isn't getting enough light, but until I get that green house built, it has to stay under the LEDs until there is a greenhouse. Greenhouse is currently in pieces waiting to be assembled because it's so freakin hot outside, I can't take but an hour or so outside before feeling like I'm gonna die, but next week there is promise of mid 80's, I'll finally get things done ... when I'm not doing other chores of course, LOL

[camille1585]

Those burn marks alomost look like the LED lamp has a few 'hot' diodes putting out more light than the others!

I've also burned some plants at work under LEDs (I work in R&D for an indoor farming company) when we stuck a new crop type under our standard 250 µmol/m2/s PAR, and even with the lights 40cm above the plants, they burnt to a crisp! So we quickly turned down the light intensity...

[SouthPark]

The topic of 'can LED lights burn leaves'. Definitely can. It depends on the intensity of the light shining on the particular part of the plant/leaf.

Those super bright LED torches provide a good indication of their power. The brightest regular LED torch (eg. on sale from ebay etc) are so bright that they instruct people to not point the beam into our eyes ---- as that would lead to major eye damage. And --- if we were to point the very bright LED torch on our hand or arm, in close proximity ----- the hand will start getting quite warm. Even hot. Hot enough to burn leaves of orchids.

[IngieBee]

LOL, @camille1585, the leaf had pushed itself up against the panel with LEDs, so I don't think it's too much, just too close and I find the perfect circular burns to be funny. I actually don't think they're quite enough for some of my orchids, particularly my dendrobium nobile. But I hope to rectify that with the geenhouse that I never have time to build! LOL. At least the weather is cooling off.