Great initiative, and he's a great advocate.
In either direction from my office there are 'gardens' with sparsely placed trees, and between the concrete walkways is ample space with fantastic soil to grow food -- fruit trees, berry bushes, salad greens, whatever. Also within a few hundred meters of the office are no less than 6 homeless people. It always seems surreal to me.
We could feed the entire suburb on that ground, let alone the entire city's homeless community...