'For you little gardener and lover of trees,' she said to Sam, 'I have only a small gift.' She put into his hand a little box of plain grey wood, unadorned save for a single silver rune upon the lid. 'Here is set G for Galadriel,' she said; 'but also it may stand for garden in your tongue. In this box there is earth from my orchard, and such blessing as Galadriel has still to bestow is upon it. It will not keep you on your road, nor defend you against any peril; but if you keep it and see your home again at last, then perhaps it may reward you. Though you should find all barren and laid waste, there will be few gardens in Middle-earth that will bloom like your garden, if you sprinkle this earth there. Then you may remember Galadriel, and catch a glimpse far off of Lórien....'
Sam went red to the ears and muttered something inaudible, as he clutched the box and bowed as well as he could.
It seems odd to carry around a box of dirt for a year. If he was going to make any use of it, he'd need a lot. Is there any mention of how much dirt Sam got?