and miracle grow's potting soil is well known to NOT be a good choice for cannabis...it comes with time release ferts built into it and you added more, and maybe followed the directions and did not dilute...thus thoroughly fertilyzing your soil to the point it poisoned your plant. sound about right?

next time, if i were you i'd get the best standard potting soil you can (read all the info on the bag...many times they list ph level too...whitney farms is good and fairly common but the bluish grey bag is not so good, look for the mostly tan bag w/farm pics on it ) along with a cactus soil mix to blend it at 3:1 (3 parts potting soil to 1 part cactus) and toss in plenty of vermiculite or perlite...you will have good draining soil which is fresh and should be good for seedlings until the 3rd week or so before needing ferts...then follow directions and cut in half. you can always add more later if needed but ya can't take it away very easily. never soak your plants, especially at seedling stage...another common prob with new growers.

it's time to try again!

good luck