Like mrblu said, I'm sorta assuming your using Miracle-gro too... which most people would say isn't the best but if that's what you're working with you can still produce good results, however, if your using miracle-gro: I would do a mixture of like 1/2 perlite and/or vermiculite and 1/2 MG soil. Reason why is because it can get nute-burn easily from overwatering with soil like MG and the perlite/vermiculite will 'dilute' it so to speak (as well as help with drainage and getting air to the roots) - I am not a pro by any means but have done research on this for about 6 years now and watched others do their thing over the past 2 years in person. I will say that if I were to use MG soil right now, whether organic MG or regular MG, I would also buy a bag of perlite and vermiculite, do 1/4 perlite, 1/4 vermiculite, and the other 2/4 soil. ---Of course, i'm assuming you haven't transplanted out of the little cup in the picture. I hope this helps.