There should be a N-P-K (20-20-20) number that would be on the bag somewhere that would help you find out if soil is even the problem. I could be alot of things. If its bagseed anything can really happen including a plant growing up a lil then just not stop. Also your water like that one guy said. Years ago i didn't know that the water that comes out of your sink will most likely kill your plants... well atleast around here anyway. PH your water and make sure its not above 6, 6.5. Light also can cause this and heat ... not enough light and too much heat.![]()