got some leaf curl going on, i would have to say if due to watering its under watering and not over, water is as dry as could be.
Hit them today with a pretty diluted shot of MG liquid fert and a moderate watering.
another pic, another plant , same type, same issue
What variety of peppers are they? Also how often do you fertilize?
This post was edited by habjolokia on Sat, Feb 23, 13 at 13:58
Sometimes over fertilization causes this, another thing that could cause this is not enough nitrogen. What's your schedule of fertilizing? What are the NPK ratios?
Underwatering hasn't looked like that in any of my plants.
With peppers, the plants wilt and leaves hang down until dropping.
With such dark green foliage, I wouldn't guess a nutrient deficiency. Will wait for the answers Mark's questions.
I fertilize pretty liberally with Miracle Grow liquid all purpose plant food
the mix of water and fert is very watered down, probably about half of what it should be.
I also, about a month ago, added a small amount of epson salt.
thismembername, these plants are clearly over fertilized. They are too young to be suffering from under fertilization plus you stated you do fertilize them. Upward leaf curl with very dark leaves is classic of over fertilization (yes I know that black cuban is suposed to have dark leaves but these are too dark).
I would suggest removing the plant from the soil and soaking the roots in water until clean. Then re-potting and give it a little liquid calcium since calcium is not a nutrient that can move around in a plants like nitrogen and many others.
I would add a little white vinegar, 1 - 2 teaspoons, to a gallon of water, and then flush the pots. Should help free some of the excess fertilizer salts.