LED warning!!!!

[TheMad_Poet]

2023 turning ugly on me. I converted my flourescent lights to LED 6500K, started my onion plants back in late Dec, and they did great. So started my tomatoes and grew under the same lights, and all was fine, for a while. Now plants are wilting and dying, seems those LED's are way to brite for tomato plants, . Leaves curled and turned purple, got wilty and have lost a few plants. None look healthy. Google searches show the lites as the probable culprit. I used direct wire LEDs in my old florescent housings, after removing ballast and rewiring. Went out today and got some red cellophane and covered the lights to change the color and dampen the brightness. Only the tomatoes were affected, peppers and onions are all right as far as I can tell. May have to find a vendor nearby selling plants. So many good varieties I wanted to try this year from the mmmm swap. May lose them all. Hoping enuff survive under the red lite, that I can get some ripe toms to save seed from. It's always something. I had no Idea led's could cause damage like that. Been too cold to have them outside the last few days, in my unheated greenouse. Were all doing great till I had to leave them inside for 3 days running. Dag nabbit!!!

[Tormahto]

2023 turning ugly on me. I converted my flourescent lights to LED 6500K, started my onion plants back in late Dec, and they did great. So started my tomatoes and grew under the same lights, and all was fine, for a while. Now plants are wilting and dying, seems those LED's are way to brite for tomato plants, . Leaves curled and turned purple, got wilty and have lost a few plants. None look healthy. Google searches show the lites as the probable culprit. I used direct wire LEDs in my old florescent housings, after removing ballast and rewiring. Went out today and got some red cellophane and covered the lights to change the color and dampen the brightness. Only the tomatoes were affected, peppers and onions are all right as far as I can tell. May have to find a vendor nearby selling plants. So many good varieties I wanted to try this year from the mmmm swap. May lose them all. Hoping enuff survive under the red lite, that I can get some ripe toms to save seed from. It's always something. I had no Idea led's could cause damage like that. Been too cold to have them outside the last few days, in my unheated greenouse. Were all doing great till I had to leave them inside for 3 days running. Dag nabbit!!!

You likely have a shorter growing season, than I in south western Massachusetts.

I haven't even started tomatoes, yet. Usually it's about May 1st, transplanting about June 1st.

Perhaps some of your earlier to mature ones can be started again?

[pepperhead212]

The lights probably aren't too bright - just too close. I have 2 of my T8 (out of 8, of 2 sets) bulbs I had to replace (I put in 5,000k, 3600 lumens), and they were much brighter, but none of the plants were "burned" or anything else you could call it, and I've been reversing the two trays on the shelf, to equalize the light. And they start getting closer than 2" or so, I move it away another inch or so.

Here's the photo I took, showing how much brighter the LED was!
Photo shows how much brighter the LED replacement bulbs are than old T8 bulbs. by pepperhead212, on Flickr

[Labradors]

My message got lost.

I HATE my Roots Down LED lights! They burned the leaves on my winter-grown micro-tomatoes and I won't be wasting my time growing things again to get burned leaves and limited lifetimes. Although I did get some fruit, the plants all stopped producing under the LED's. When I put them on the windowsill, they thrived and put out new growth and more flowers......


Linda

[TheMad_Poet]

I am zone 5b, and usually start tom seeds no later than 1st week of april. This year I started last week of march, which is best especially for longer maturing varieties. And Brandywines. Last yr I had 2 starts of BW's. One late march, the other early APR. The march starts set way more flowers and gave me quite a bit more fruit. BW's, even cowlicks are noted for not setting fruit once it gets too hot. But, I am starting more seed today as a back up plan. And yes I had the lites just an inch above the plants to start. But moved the lights a lot hifger, and they still seemed to suffer. Have the red cellophane on now, so will see how that works. My lights are 6500k, 1800 lumens. I wish I had bought 5000k now, but the 6500k were the only ones that came in a 10 pack, so saved some money, not worth it now that I know. The 6500k are known to cause problems for plants, turning leaves purple and curling. Hopefully the red cellophane will help. I now have them as high as I can get on the shelves, so more like 6" of head space. This latest coldspell kept the plants indoors, which was no help. The soil is now too damp, and damping off may have started. In a hot green house they dry out quickly. In my back room not. OK, out to prepare soil and start new round of seeds.

[Seven Bends]

2023 turning ugly on me. I converted my flourescent lights to LED 6500K, started my onion plants back in late Dec, and they did great. So started my tomatoes and grew under the same lights, and all was fine, for a while. Now plants are wilting and dying, seems those LED's are way to brite for tomato plants, . Leaves curled and turned purple, got wilty and have lost a few plants. None look healthy. Google searches show the lites as the probable culprit. I used direct wire LEDs in my old florescent housings, after removing ballast and rewiring. Went out today and got some red cellophane and covered the lights to change the color and dampen the brightness. Only the tomatoes were affected, peppers and onions are all right as far as I can tell. May have to find a vendor nearby selling plants. So many good varieties I wanted to try this year from the mmmm swap. May lose them all. Hoping enuff survive under the red lite, that I can get some ripe toms to save seed from. It's always something. I had no Idea led's could cause damage like that. Been too cold to have them outside the last few days, in my unheated greenouse. Were all doing great till I had to leave them inside for 3 days running. Dag nabbit!!!

Without pictures it's hard to know, but when you say "Leaves curled and turned purple, got wilty," it sounds more like edema/intumescence rather than burning the leaves from the lights being too close. Are you sure your problem is the intensity of the light?

If your problem is edema/intumescence, you need to add UV light and/or far-red light. Best way to do that is to put your plants out in the sun or in a sunny windowsill. If it's too cold outside, put them out in the sun in a plastic, translucent file box with row cover over the top, or in one of those portable plastic tunnels. Even if your plants look gnarly, they could outgrow it; it's worth a try. If your existing plants are too far gone, try it with your new starts.

The other thing that affects edema/intumescence is moisture. It could be the soil has been too wet, or the humidity too high. Some people say edema can be caused by letting the plants dry out, and then suddenly increasing the moisture. You may be able to reduce the problem in the future by adjusting your watering. Cold temperatures in your growing area could be a factor, too. It could be that your old, non-LED lights ran hotter and therefore kept things warmer.

If the problem is light intensity/closeness to the plants, the solution is to move the lights higher. If you tried that and it didn't work, it doesn't seem like that was the problem. What is your thinking in adding red cellophane? That will allow red light to pass and will absorb/block the other wavelengths.

[TheMad_Poet]

2023 turning ugly on me. I converted my flourescent lights to LED 6500K, started my onion plants back in late Dec, and they did great. So started my tomatoes and grew under the same lights, and all was fine, for a while. Now plants are wilting and dying, seems those LED's are way to brite for tomato plants, . Leaves curled and turned purple, got wilty and have lost a few plants. None look healthy. Google searches show the lites as the probable culprit. I used direct wire LEDs in my old florescent housings, after removing ballast and rewiring. Went out today and got some red cellophane and covered the lights to change the color and dampen the brightness. Only the tomatoes were affected, peppers and onions are all right as far as I can tell. May have to find a vendor nearby selling plants. So many good varieties I wanted to try this year from the mmmm swap. May lose them all. Hoping enuff survive under the red lite, that I can get some ripe toms to save seed from. It's always something. I had no Idea led's could cause damage like that. Been too cold to have them outside the last few days, in my unheated greenouse. Were all doing great till I had to leave them inside for 3 days running. Dag nabbit!!!

Without pictures it's hard to know, but when you say "Leaves curled and turned purple, got wilty," it sounds more like edema/intumescence rather than burning the leaves from the lights being too close. Are you sure your problem is the intensity of the light?

If your problem is edema/intumescence, you need to add UV light and/or far-red light. Best way to do that is to put your plants out in the sun or in a sunny windowsill. If it's too cold outside, put them out in the sun in a plastic, translucent file box with row cover over the top, or in one of those portable plastic tunnels. Even if your plants look gnarly, they could outgrow it; it's worth a try. If your existing plants are too far gone, try it with your new starts.

The other thing that affects edema/intumescence is moisture. It could be the soil has been too wet, or the humidity too high. Some people say edema can be caused by letting the plants dry out, and then suddenly increasing the moisture. You may be able to reduce the problem in the future by adjusting your watering. Cold temperatures in your growing area could be a factor, too. It could be that your old, non-LED lights ran hotter and therefore kept things warmer.

If the problem is light intensity/closeness to the plants, the solution is to move the lights higher. If you tried that and it didn't work, it doesn't seem like that was the problem. What is your thinking in adding red cellophane? That will allow red light to pass and will absorb/block the other wavelengths.

Really not sure of anything, and yes could be a combination of things. I have read since that the bright 6500k LED's are known to cause purpling and curling of the leaves, and raising the lite is a solution. Adding the red was to move the color down, toms like the red spectrum the most. Too much water was not the case until the last few days. I had watered heavy in the greenhouse cause they were drying out quickly with temps near 80 inside. Had to bring them in and they never dried out in the house. Description, leaves purpled, curled, and twisted. And the stems got really thick looking in an un even way. Been starting tom seeds for 20 years, and never saw stems look like that. And there is a moldy smell in the green house and my back room, that my wife said she has never noticed in previous years. Then branches and leaves started to fall off with the slightest of touches. I just tossed out about half the plants I had started, kept the best looking of the bunch. Some varieties were affected more than others, and a few plants look normal. Many were stunted and not worth saving. Hoping the rest will recover. Those thickened stems looked blotchy white, when I rubbed with my finger they seemed wet and slimy. And the stem hairs were missing on these thick portions Really wierd stuff. The potting mix was sunshine #4, from Lowes. Lowes keeps the bags in an area where the sun and rain can get to it, plus tonite I read the label it was expired when I bought it, wondering if the batch was moldy a bit when I bought it. New seeds are started, and will be potted in a new batch of mix. What a pain, this is sposed to be fun, LOL!!! ADD: Checked out edema pics, definitely not that. I manage to get a bit of damping off every year, but never seen it look like this.

[TheMad_Poet]

Just googled led too bright and tomato plants and yes this is exactly what happened, and tho I raised the lights they were prolly still too close. The cellophane should lessen the effect, but I waited to long to realise what was happening. Lesson learned. https://www.sandiaseed.com/blogs/news/c ... much-light

[Sue_CT]

Have not had a good year of seedlings since I switched to LEDs 2 or 3 years ago. Have not figured it out yet. My seedlings look a bit leggy so I put the lights closer and they burn or turn purple. I hope to have better luck this year but since I started a much smaller batch this year, if I start having problems just going to put them in a South facing window and the heck with them, lol.

[zeuspaul]

My plants do well with LED grow lights. I use the standard screw in light bulbs. Each bulb has several different diodes so there is a mix of different light waves. I have several different brands with slightly different curves. Some favor red and some favor blue but they are similar.
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[CrazyAboutOrchids]

I switched to LED lights this year - replaced 4 4 foot T8's with 2 Spider Farmer SF600's. So far so good. They are in the 5000K spectrum though and do include far red in their strips. Knowing where to hang them has been a challenge. My starts are getting their 2nd potting up this week and then will start their days outdoors.

[Seven Bends]

Just googled led too bright and tomato plants and yes this is exactly what happened, and tho I raised the lights they were prolly still too close. The cellophane should lessen the effect, but I waited to long to realise what was happening. Lesson learned. https://www.sandiaseed.com/blogs/news/c ... much-light

Interesting that purpling would be caused by too much light. Most other info sources say you will get bleaching/fading/yellowing, or burning & brown patches. I'm not finding any non-blogger/non-youtuber sources that talk about purpling as a symptom of light burn, but it sounds like @Sue_CT is having the same problem. Maybe the ag extension services, etc. just haven't caught up to this particular symptom of LED lights yet.

I'm not disagreeing with you about LED lights causing problems sometimes. Certainly there have been a lot of complaints in the last few years, along with the success stories. It's just that your description of symptoms doesn't really sound like light burn. The added information about the soil and the white stuff seems to point away from the lights also.

I don't think the red cellophane is the solution, and I think it may compound the problem. Yes, you'll reduce the intensity of the light, but you're doing it by blocking almost all of the non-red light. Your plants need blue light to grow.

[Sue_CT]

I guess I didn't say it clearly, I have been having burn and wilting AS WELL AS purpling. I don't know that the purpling had anything to do with the lights, but I assume the burning did.

[TheMad_Poet]

Have not had a good year of seedlings since I switched to LEDs 2 or 3 years ago. Have not figured it out yet. My seedlings look a bit leggy so I put the lights closer and they burn or turn purple. I hope to have better luck this year but since I started a much smaller batch this year, if I start having problems just going to put them in a South facing window and the heck with them, lol.

Sue lets put our heads together and maybe we can figure it out. What kind of LED's are you using? Mine are not grow lights, just general lighting at 6500 K. I have the red cellophane filtering the lights now, but I may just try a piece of window screen, or clear greenouse plastic, anything that will cut down a bit on the transmittance. I like the LED's, way cheaper to run, and no thermal heat, the burn is all "sunburn" on the plants. The red cellophane is more clear than red, and I have it on double and it has cut way back on the brightness. May try single or screen, or single and screen together. I attached it with some metal clips that I had bought for the green house. Have a new batch of seeds planted, so will be running some new seedlings under them, soon. Most of my plants showed sunburn on the "seed leaves" first, but I didnt think it was caused by the lights. It was Tho. One article says keep the lites 12-18" above the plant tops. My shelves are not tall enuff for that so I will be using something over the lites instead.

[TheMad_Poet]

Yep, 1st was the seed leaves turning white, seen that with young plants put out into direct sun without hardening to the UV outdoors. Then the leaves started curling, and twisting with the bottoms trying to face the lites. The bottom of the leaves and the stems are what turned purple. Also the up side of some of the leaves got a yellowish hue to them. Then I noticed some of the stems thickening and discolored, Eventually the wilting, and branch fall off started. Due to the damage from the lites. The very bright 6500K lites are the worst, I understand. Wish I had bought the 5000k, but didnt. BUT, articles read say use some type of shade screen, and distance and all should be better. Just have to figure that out yet. Sue, what what is the Kelvin rating of your lites? My wife read an article that said the purplng was a reaction to the bright lites, and the plants are producing the same anthros to protect the leaves, that are found in blueberries and blue tomatoes.

[Sue_CT]

I will check the lights, pretty sure they are 6500. No problems currently, so will address if they happen I guess. Hard to figure out now what happened a year or more ago. Current seedlings are leggy and very close to the lights, but no signs of burning yet. Just took a pic, you can see all the seedlings are the same height from light, but the Black Cherry and the GGWT seedlings look pretty good, SOTW right next to them is leggy. There are a couple of browning cotillons, but that is probably just the expected progression of them starting to drop off.

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[TheMad_Poet]

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Here are some pics. I had 150 tomato seedlings, pitched half of them, and kept the best to see how theyd do. Notice the clips holding the cellophane onto the lites. Cellopahne bought at a hobby store, used to wrap presents or flower boquets. Also shown are burnt seed leaves, and upside down twisted branch with he bottom of the purpled leaves facing up. The worst ones of course were way worse. Not sure if these will ever grow right. If growing tips and plant in general are too damaged.

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[TheMad_Poet]

I will check the lights, pretty sure they are 6500. No problems currently, so will address if they happen I guess. Hard to figure out now what happened a year or more ago. Current seedlings are leggy and very close to the lights, but no signs of burning yet. Just took a pic, you can see all the seedlings are the same height from light, but the Black Cherry and the GGWT seedlings look pretty good, SOTW right next to them is leggy. There are a couple of browning cotillons, but that is probably just the expected progression of them starting to drop off.

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After the disaster I have had I highly recommend you put something over the lites as I have done. The 6500k lites are just too strong. My problems took several weeks to develop, and damage was done. Started my seeds a month ago, so it took 3 weeks or so b4 crap hit the fan. You could us clothes pins to attach, just a piece of clear plastic might cut back the intensity. Got some GGWT also, and surprisingly, they were one of the varieties that had the least damage. Slankards was another. My Brandywine Cowlicks were all toasted. Had 15 started for me, family and friends.

[Sue_CT]

I don't really see burning on those plants, at least not on the true leaves. The cotillons are turning brown, which they do before they fall off naturally. The wilting and purpling is obvious, though.

[svalli]

I have been trying to find solution to this problem for ten years now.

There is already a lot of discussion in another thread viewtopic.php?t=4096

Some varieties get intumescence with UV-B deficient light and it has been researched in many universities.
https://www.google.com/search?q=intumescence+tomato+LED

As solution I have found that I have to have a fluorescent tube parallel to the LED-tubes and even I have the lights close to my plants, there is no problems.

This year I experimented with LED grow lights with UV-A LEDs, but it did not help. I have now ordered lights which have some FAR-red LEDs with cool white ones. I'm hoping that those could be used to replace the need for the fluorescent tube.

Sari