Pepper seedlings - leaf discoloration - Ask Extension
Hello!My four-week old pepper seedlings are showing signs of distress. The true leaves appear burned and the cotelydin leaves are yellowing. These sym...
Knowledgebase
Pepper seedlings - leaf discoloration #556446
Asked April 28, 2019, 9:06 AM EDT
Hello!
My four-week old pepper seedlings are showing signs of distress. The true leaves appear burned and the cotelydin leaves are yellowing. These symptoms first started to appear three days ago. They are being grown under 4 T5 flourescent bulbs on a 16/8 hour on/off schedule with a fan running intermittently. Currently, the lights are about 4 inches above the tallest seedlings.
I water them when the plugs dry out, usually once a day, making sure the soil mix has had a chance to dry before additional watering. The plugs trays have holes and drain effectively. The soil media is a reputable organic mix - Berger OM. I have fertilized twice since the first true leaves appeared two weeks ago, using Fox Farm liquid Grow Big 6-4-4 at half strength per bottle recommendations for seedlings. The seedlings responded well to the first fertilization. The second fertilization was last Monday, and the leaf problems started to appear three days later.
Since the leaf problem appeared, I have changed the light schedule from 16/8 to 12/12, fearing too might light might be the cause of the leaf discoloration.
What do you think is happening? Is it light - too much? Is it water - too much/little? Is it fertilizer? And what can I do to reverse the damage and prevent additional damage? I have 16 varieties of peppers and all are affected. Thank you in advance for your help!
My four-week old pepper seedlings are showing signs of distress. The true leaves appear burned and the cotelydin leaves are yellowing. These symptoms first started to appear three days ago. They are being grown under 4 T5 flourescent bulbs on a 16/8 hour on/off schedule with a fan running intermittently. Currently, the lights are about 4 inches above the tallest seedlings.
I water them when the plugs dry out, usually once a day, making sure the soil mix has had a chance to dry before additional watering. The plugs trays have holes and drain effectively. The soil media is a reputable organic mix - Berger OM. I have fertilized twice since the first true leaves appeared two weeks ago, using Fox Farm liquid Grow Big 6-4-4 at half strength per bottle recommendations for seedlings. The seedlings responded well to the first fertilization. The second fertilization was last Monday, and the leaf problems started to appear three days later.
Since the leaf problem appeared, I have changed the light schedule from 16/8 to 12/12, fearing too might light might be the cause of the leaf discoloration.
What do you think is happening? Is it light - too much? Is it water - too much/little? Is it fertilizer? And what can I do to reverse the damage and prevent additional damage? I have 16 varieties of peppers and all are affected. Thank you in advance for your help!
Denver County Colorado
Expert Response
We think the discoloration may be either too much fertilizer, too much water, too little air or maybe a combination of all three. The following article from CSU Extension recommends using fertilizer at "1/4 to 1/2 strength." We also notice that the soil surface in your photos looks a little greenish which suggests to us that it's not drying out. We encourage you to back off the fertilizer and adjust the watering strategy. If you still are using the tray covers, just take them off at this point and increase air circulation. See this link: https://planttalk.colostate.edu/topics/annuals-perennials/1034-starting-seeds-indoors/
Thank you very much for your reply and evaluation. Much appreciated!
Thank you very much for your reply and evaluation. Much appreciated!
