mg is 3 month time release . haven't you seen the threads where mg kills peoples plants! There are at least 7 posts a week on problems with mg. Your plant is being overfertilized by the soil more nutes will kill it transplanting to the same mg soil will most likely kill it too. 1/3 perlite, 1/3 peat moss BOTH NON MG PRODUCTS and 1/3 of some compost add 1 tablespoon of dolomite lime to a gallon of mix. After the transplant (maybe a week)when there is new growth then you can begin with fertilizer. You need to check your ph too buy a pool ph tester kit and test the runoff to get an accurate reading it should be at 6.4 to 7.0 for soil.