Its my first grow and my plants are a couple of weeks old and the leaf tips are going brown and some of the leaves are going yellow, anyone have any suggestions please.

I am growing them in polystyrene cups with good soil and i have given them Miracle Grow once at half the recommended strenghth. I dont yet have a light so they are on the window sill, but they do not appear to be stretching so i dont think this is the problem.
dj2883 Reviewed by dj2883 on . Leaf tips going brown Its my first grow and my plants are a couple of weeks old and the leaf tips are going brown and some of the leaves are going yellow, anyone have any suggestions please. I am growing them in polystyrene cups with good soil and i have given them Miracle Grow once at half the recommended strenghth. I dont yet have a light so they are on the window sill, but they do not appear to be stretching so i dont think this is the problem. Rating: 5