Sometimes you get lucky with the right conditions for a seed. I first germinated in plastic bag with peat moss and vermiculite with a few small holes for air circulation and constant heat mat of 85F. Then as soon as first root and top growth emerged I planted on a deep 4x4x10 pot with potting soil covering about 80% of the seed. Garcinias tend to have long taproots so it's good to give them room to grown deep. In some GHombronianas that I have transplanted at 4 inch tall the tap root is 2-3 times the size of the upper growth.