Growing anything on mars will likely depend upon both near total closed cycle recovery of water plus developing some water resources on Mars. Water transported to the Mars will inevitably suffer some loses, no matter how carefully managed. There is water on Mar, but we won't know how difficult it will be to "mine" until we are there, and practical methods won't be part of the first missions, although they may have to see if they can recover some from the environment.
If - IF - water can practically be mined there, it will be a huge step, because it will make food production more practical and will potentially be a source of oxygen, which will also be lost over time, no matter how good the systems.
There are two approaches to Mars. One is frankly one-way suicide missions which I doubt will be planned. The other is a mission with a return trip. That might me covertly planned as essentially a one-way, the return trip being planned but played so closely to the doability line as to be barely acceptable. But a lot of aerospace stuff has been done so close to the certain failure boundary that there are precedents.
I somehow don't think dependence on Mars grown food is in the cards until reliable return can be assured. Too much could go wrong. Every mission will have to be self-contained, with at least an emergency get-out always in reserve. If they grow anything there, it will likely be some sort of edible pond scum.
