Our back yard near Johnson City, in upstate New York, is a small yard, and a lot of it is shaded. We only have a small spot with sun, which is mainly in an area occupied by a patio. So, if we want to grow anything in our back yard in full sun, it has to be in pots.
We do grow geraniums, petunias, and a handful of veggies. (most of our gardening is done in a community garden.)
A few years ago, we bought two Earth Boxes. The company is located near Scranton, PA (about an hour south of us) and I can highly recommend this product (noting that I am getting no compensation whatsoever for this.). A lot of their business seems to be with schools, and I can applaud any company that brings gardening to young students. As for our experience:
This is a self-contained system - there is a pipe where you add water once a week or so, and it waters itself. Behind the soil mix they sell and refill kits, you don't even have to add fertilizer. Kits are available for both organic and non organic gardeners.
We have grown some nice peppers and eggplant, with less luck (for some reason) with spinach and with tomatoes. Our peas this fall were planted too late and we got hardly any harvest at all, but that wasn't the Earth Box's fault.
We do need to get a refill kit though - this last gardening season didn't work well for us.
corn salad (mache) growing in one of the Earth Boxes - we had three plants survive down to 6 degrees above zero (-14.4 Celsius) without any protection other than snow. This is the first time we've ever grown this green, and are curious to know how it will do the rest of the winter. Maybe, with some protection (the box is right up against the house) it will be a good overwintering crop for us.
Not only did the corn salad surprise us, but also what we found in another pot -
Parsley. Not enough to use, but I'm sure it will start growing a bit in early spring before starting to bolt. (Parsley is a bi-annual).
You don't need a big area to garden. You don't even need to have a back yard with soil to garden. There are a lot of online sources of information for container gardening. Start small, get comfortable, and you'll be surprised at what you can harvest.
Even in the middle of winter.