Sure this will cause some controversy but here are the results of applying elemental magnesium/gypsum and nitrophoska granular fert to both my trees and my next door neighbours in the ground...two of the lemons were practically dead and mine had spindly growth and looked depressed until i pruned it hard and gave it the above...Applied every three months...handful of each....You be the judge...They are all dwarf trees.The mandarin with all the fruits=Hardly gets any sun!

http://s1026.photobucket.com/albums/y326/laidbackdood/

LBD,The trees look nice and healthy, I'm not sure what you mean by the word "elemental". Elemental magnesium would be a metal. - Millet (583-)

I dont know what i mean by that either magnesium fillings would be a better definition then.
Its does feel like metal fillings though millet...The guy that sold it to me,said it would dissolve over time with exposure to rain and oxygen.