Potted plants have thin stalks?

My wife works in a daycare and the kids have planted marigolds. Once sprouted the stalks (the marigolds, not the kids) are thin and discolored and the plant soon dies... I'm thinking they need more fertilizer and sun (we live in the sun-deprived Pacific NorthWet), since all the plants are doing the same.





Am I right or, does she need to do something else to them (the plants not the kids)?





I'd like to have her become the hero of the daycare (to the kids, and the Marigolds).

Potted plants have thin stalks?
Marigolds need lots of sun. Some sun, potting soil, and plant food in the water should be the best for them.