Why did your plant die when you watered it Miracle-Gro?

It could be many things...

Dirt - Maybe the soil was lacking key nutrients. I recommend getting dirt from outside and mixing it with soil from a compost pile or organic fertilizers. Commercial fertilizers can sometimes have harmful chemicals.

Water - Did you water your plant enough? Our maybe you watered it to much. If your plant is inside, water it about 2 times per week. If your plant is outside, water it every day it does not rain.

Bugs - If your plant was exposed to insects, some of the bugs may have eaten your plant, causing it to die. Some bugs are in the soil and eat the roots. Here's what you can do. Dig up some dirt from outside. Mix it with your choice of fertilizer. Put the mix into a colander with small holes. Shake it well. Then pick out any bugs you see in the dirt. Dampen the soil so more bugs come out. After you have gotten the bugs out fill your pot HALF-WAYwith the dirt. Add 3-5 worms. Then fill the pot the rest of the way. (Worms don't hurt you plant in anyway, their waste helps the plant.)