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Leaves are yellowing then wilting up.

BELOW: If you zoom in on the leaf you can see white organisms along the midrib and veins.

Indoor grown under LED lighting with air conditioning.

These plants are in Miracle Grow Potting Mix with 6 mo fertilizer. I use FoxFarm "Big Grow" 8-4-4. It is possible the problem is photoinhibition as I doubled the light intensity a couple of days ago. I keep the lights on 24/7. I moved them outside in the shade to see if they will recover.

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I am experimenting with 2700K 90 CRI and 3000K 80 CRI strips of LEDs. I am trying to find the most efficient height and intensity. I made some very flexible fixtures where I can easily adjust height and light intensity.

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The "white organisms" were nothing. They were reflections off the trichrome.

Below is a close up. It's clearer if you click on the photo.

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The plants that I moved outside recovered. They look healthy now. Not very big but they were kept in the shade and 3" peat pots. I'm in Tampa so growing season does not start again until September.

I had the lights on 214/7. Tomato plants do not like a 24 hour photoperiod. Added a timer that shuts the lights off from midnight to 6 am.

This is a subsequent planting. The seeds for these sprouted on or about June 14th.
These pictures were taken July 5th (top) and July 17th (bottom). The partitions are 24" high. So the 16 watt plants are over 12". No yellowing.

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They would probably bigger then 12". I left them in the 1" peat pellets too long, they were root bound and about 3" high before I transplanted. Also I have been having problems with the peat pellets. The roots were having a hard time break through the netting that hold the peat. From now on I will transplant the seedlings within 1 week and I will remove the netting.

  • How are the roots doing? If it doesn't need nitrogen, it might have been overwatered, and the roots might be rotting. Jun 20, 2019 at 1:08
  • I see some new growth that looks healthy. When did you add the 8-4-4 what is the formula of the fertilizer in the soil? That first number has to be lower than the other 2 numbers. N has to be lower than P and K; 2-5-4 for example. Otherwise you are getting vegetative growth not reproductive growth.
    – stormy
    Jun 28, 2019 at 22:03
  • @stormy I added another photo with better lighting. It's the new growth that yellows. I just received a timer to turn off the lights for 6 hrs. a day. I'm thinking the problem may be 𝘊𝘰𝘯𝘡π˜ͺ𝘯𝘢𝘰𝘢𝘴 π˜“π˜ͺ𝘨𝘩𝘡 𝘐𝘯𝘫𝘢𝘳𝘺. I will be transplanting 20+ seedlings into grow bags today. Jun 29, 2019 at 19:38

1 Answer 1


This looks to be simply lack of balanced fertilizer; NPK. Have you fertilized with anything? Even non balanced fertilizer such as fish fertilizer or bone meal?

I would use Osmocote 14-14-14. Use at half the direction's advice. The cotyledon supplies enough chemistry to the baby plant until that plant is on it's 2 or 3rd set of leaves. Then YOU have to carefully with knowledge supply that plant fertilizer or this will happen.

Looks as if you have correctly used potting mix medium and NOT garden soil. Did you use any rock or gravel at the bottom of the pot beneath the soil and above the drain hole? If so, simply turn that pot over holding onto the plant and dump out the rock. Replace the volume with potting soil; sterilized potting soil with NO fertilizer added (you want to be fully in charge of fertilizer) and no funky gimmicks like water holding sponges and water holding gells. Plain, cheap sterilized potting soil medium.

Water thoroughly and do not water again until that pot feels LIGHT.

Fertilize with a BALANCED fertilizer. Osmocote 14-14-14 works best for those not familiar with the chemistry of fertilizers. Otherwise, Dr. Earth's 5-5-5 is good and when they get larger and flowering, switch to Growilla 2-5-4. This promotes reproductive growth for more tomatoes.

Where fertilizer is concerned; Less is Best, More is Death and None is Dumb.

If you've added fertilizer, then you have an entirely different problem. Insects will attack plants that are not vigorous and healthy. This is not being caused by those tiny dots (white fly?). The insect is simply a secondary problem.

Spray your plant, at night, out of doors with a properly mixed NEEM. Lie it on its side and make sure to spray beneath the leaves, even the top of the soil. Send a picture in *a few weeks after fertilizing, watering ONLY when that pot and soil and plant become obviously lighter and after spraying with NEEM.** Read the label on NEEM 5 times! Grins. That is what every pesticide operator is taught to do every single time they reach for a bottle of pesticide/herbicide/miticide/fungicide. These 'cides' mean KILL.

Healthy plants rarely have insect problems.

Growing in artificial light is great but you HAVE to have a major fan blowing on those plants; 24/7.

  • These plants are in Miracle Grow Potting Mix with 6 mo fertilizer. I use FoxFarm "Big Grow" 8-4-4. It is possible the problem is photoinhibition as I doubled the light intensity a couple of days ago. I keep the lights on 24/7. I moved them outside in the shade to see if they will recover. I am switching from peat pots to grow bags (see added pic upper right). I do not want to pay over $10 per cu.ft. of potting soil. I have a new bag of Kellogg Potting Mix which I will mix with peat moss and compost and or worm castings. Jun 20, 2019 at 1:01
  • This makes far more sense, Misunderstood! First do not keep the lights on 24/7. Big no no. 18/6 is fine at the beginning just to get them vigorous and healthy. Towards the end of the season 12/12 promotes reproductive growth. Plants need their dark time. What plants got the chance to grow in the INTENSE light 24/7? None. What intensity did you start with and what intensity did you change your lights to ? How close were the lights to the plants. Out of doors under a secure shaded area is great. Don't add anything at all to the potting soil! No need for peat pots or grow bags...$$$
    – stormy
    Jun 20, 2019 at 6:22
  • 8-4-4 is too heavy with nitrogen in relation to the P and the K. This promotes vegetative growth not reproductive growth. I would bring your tomatoes back inside to their normal spots, add a fan, add Osmocote at 1/4 the directions, 2-5-4 Growilla would be a gentle balanced fertilizer. Moving plants is one of the biggest stressors of plants. They were not made to move but to stay in one place. Indoors to out of doors is a big deal and any sun on them could burn them, kill your tomato plants. Out of doors back to the indoors as well is stressful and needs acclimatization first.
    – stormy
    Jun 20, 2019 at 6:29
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    RE: "π‘£π‘’π‘”π‘’π‘‘π‘Žπ‘‘π‘–π‘£π‘’ π‘”π‘Ÿπ‘œπ‘€π‘‘β„Ž π‘›π‘œπ‘‘ π‘Ÿπ‘’π‘π‘Ÿπ‘œπ‘‘π‘’π‘π‘‘π‘–π‘£π‘’ π‘”π‘Ÿπ‘œπ‘€π‘‘β„Ž". I live in Tampa and tomato grow season starts in September. Three weeks ago these plants were still seeds. When I reduce the photoperiod (or move them outdoors) they will begin to bloom. That is when I will change to FoxFarm's "π‘‡π‘–π‘”π‘’π‘Ÿ π΅π‘™π‘œπ‘œπ‘š" 2-8-4. About the 18/6 photoperiod, the science is mixed. Cornell said regarding lettuce germination: "πΉπ‘œπ‘Ÿ π‘‘β„Žπ‘’ π‘Ÿπ‘’π‘šπ‘Žπ‘–π‘›π‘–π‘›π‘” 10 π‘‘π‘Žπ‘¦π‘ , π‘‘β„Žπ‘’ π‘™π‘–π‘”β„Žπ‘‘ 𝑖𝑛𝑑𝑒𝑛𝑠𝑖𝑑𝑦 𝑖𝑠 π‘šπ‘Žπ‘–π‘›π‘‘π‘Žπ‘–π‘›π‘’π‘‘ π‘Žπ‘‘ 250 ΞΌπ‘šπ‘œπ‘™/π‘š2/𝑠. Jun 20, 2019 at 23:44
  • 1
    Cont'd. π‘‡β„Žπ‘’ π‘β„Žπ‘œπ‘‘π‘œπ‘π‘’π‘Ÿπ‘–π‘œπ‘‘ (π‘œπ‘Ÿ π‘‘π‘Žπ‘¦ π‘™π‘’π‘›π‘”π‘‘β„Ž) 𝑖𝑠 24 β„Žπ‘œπ‘’π‘Ÿπ‘ . π‘†β„Žπ‘œπ‘Ÿπ‘‘π‘’π‘Ÿ π‘β„Žπ‘œπ‘‘π‘œπ‘π‘’π‘Ÿπ‘–π‘œπ‘‘π‘  π‘Žπ‘Ÿπ‘’ π‘Žπ‘π‘π‘’π‘π‘‘π‘Žπ‘π‘™π‘’ 𝑖𝑓 π‘‘β„Žπ‘’ π‘™π‘–π‘”β„Žπ‘‘ 𝑖𝑛𝑑𝑒𝑛𝑠𝑖𝑑𝑦 𝑖𝑠 π‘–π‘›π‘π‘Ÿπ‘’π‘Žπ‘ π‘’π‘‘ π‘‘π‘œ π‘π‘Ÿπ‘œπ‘£π‘–π‘‘π‘’ π‘‘β„Žπ‘’ π‘ π‘Žπ‘šπ‘’ π‘‘π‘œπ‘‘π‘Žπ‘™ π‘‘π‘Žπ‘–π‘™π‘¦ π‘Žπ‘π‘π‘’π‘šπ‘’π‘™π‘Žπ‘‘π‘’π‘‘ π‘™π‘–π‘”β„Žπ‘‘" Source: π‘―π’šπ’…π’“π’π’‘π’π’π’Šπ’„ 𝑳𝒆𝒕𝒕𝒖𝒄𝒆 π‘―π’‚π’π’…π’ƒπ’π’π’Œ cea.cals.cornell.edu/attachments/… I recently completed building my LED fixtures for researching growing efficiently under LED lighting. I have another 20 seedlings ready for π‘β„Žπ‘Žπ‘ π‘’ 𝐼. Jun 20, 2019 at 23:53

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