I doubt they'll actually be growing them in the dirt of mars. More likely they'll be bringing dirt with them to mars and plant them in pots or something in a colony of some sort.
As I said, the problem with that is that it would mean a lot of extra weight on the ship carrying the supplies, not to mention a plant can only grow so big in a pot (especialy if they intended to actually depend on the plants for necessary nourishment.
WOW, this sounds really awesome. I have no idea to how they are gonna do it or why they haven;t done it yet but I'll sure try some vegetables from Mars if they fit my budget.
Did you even read the article, freesoul? The reason they haven't done it yet is because they haven't needed to and because it would be difficult and expensive. Food grown on Mars, assuming it was possible, would not taste any different than food from Earth. It would just be ten times more expensive. The only reason to grow plants on Mars would be to make food for humans living on Mars (anyone seen Mission to Mars?), but otherwise, it would be a pointless and expensive endeavour.