I've grown wheat at home (as a green manure) and it is easy to grow (easier than lawn).  The nutritional yield is commensurate with fruit and veggies when used as part of a crop cycle, particularly when overlapping cropping is used (grow tomatoes, then seed with grain when the tomatoes are fruiting).

So yes, most of our calories come from grain (actually, most of mine come from root vegetables these days) and urban farming can only be part of the food story.  But urban farming can use space which is otherwise unused, or worse, has the same resources spent on maintaining worthless 'green space'.  It also connects people with their support systems.

The Road to Wigan Pier by George Orwell
NY:  Berkley Publishing Corp, 1961
(80)  One thing that probably could be done and certainly ought to be done as a matter of course, is to give every unemployed man a patch of ground and free tools if he chose to apply for them.  It is disgraceful that men who are expected to keep alive on the P. A. C. [Public Assistance Committee] should not even have the chance to grow vegetables for their families.

Solar IS Civil Defense

Lettuce and herbs on your windowsill or in your planter(s). Tomatoes in planters. After that, you might want to visit some of the past ET diaries on the subject. I did a series of 3 or 4 about three years ago.

paul spencer

I love this movement. Flowers are lovely, but so are vegetables and fruits and I wish I could see as many fruits and vegetables growing on German balconies and terraces as flowers.

'tis strange I should be old and neither wise nor valiant. From "The Maid's Tragedy" by Beaumont & Fletcher

You should be able to get some variety even in a fairly small area. There's no sense really in just growing one thing. Lettuce and other salads can be grown between other plants - and anyway you don't want too many at one time because half of them will bolt before you can eat them.

In terms of stuff that will keep for the winter, we keep in a simple dry, no-freeze storage space, potatoes, onions, squash and beans (the white haricot kind, but have also done red beans or the Italian kind called borlotti). Green beans are fine in storage jars.

If you keep fish in your supply tank you get free symbiotic water cleaning and plant fertilization too.

With sufficient water you can even out day-night temperature swings to avoid heating and cooling.  You can heat the water rather than the air in the greenhouse and thus reduce losses from the glazing (because you keep the roots warm but let the leaves cool down).  watering the roots rather than top watering of course reduces fungal problems.

Then I have a simple wax piston type vent opener for super hot days.

This system has been running almost maintenance free for 5 years (the inlet occasionally gets roots in it).

Spending more on glazing insulation (adding an extra layer of plastic film on the inside, or using triple rather than double wall PC) is typically better value than spending more on the control system.