Judging from what i know about miracle grow id say its nute burn mg is not really good for herb my friend the soil is usable to a degree but thats it...so id say flush the soil and see if that helps...cause yea miracle grow on a plant that small and young.... burned it up so flush the soil and get some real nutrients like fox farm or floranova or advanced nutrient and start with a weaker dose than reccomended for the first week or so of feeding then work you way up to the feeding table reccomendations...