Quote Originally Posted by Italiano715
... Even if it is only the first set of true leaves, in my opinion it's natural to lose them also....Don't cut or pluck them either.
One of my mentors once told me I could tell the health of the seedling, and how I was taking care of their needs...by watching the cotyledon. Keep an eye on 'em, as they show the first signs of stress on the young plant.

The cotyledon will show when you do something out of the norm, like overwatering, underwatering, too many nutrients, heat stress.
But they can't tell you what the problem is...just that there's a potential problem. :thumbsup: