If you have a balcony, you can grow a garden. The key is to maximize the amount of space you have available. Do not think of vegetables as only springing forth from the soil beneath your feet.
To get tomato plants to grow upside down, drill a hole in the bottom of a plastic container. Make a hole in the bottom of a container large enough to slip the plant through, but small enough that you do not lose your soil.
Cut a piece of garden fabric or plastic a little larger than the hole in the container. Make an X -shape cut in the plastic, and slip it over the tomato plant. Next, place the plant with the plastic, upside down through the hole in the bottom of the container.
Hang your container with the tomato facing downward and fill the top of the container with soil. You will water your tomato plant at the top of the container.
Cucumbers will do well if they have some kind of trellis to climb upon. You can use mesh garden fencing, chicken wire or sticks. Plant the cucumbers in mid-size containers. As they grow, help them onto the trellis. If you have railing surrounding the balcony, you can train them to grow around it.
Growing bush varieties of vegetables will also use less space. Look for bush cucumber and bush beans to maximize space. Root vegetables will grow in containers, if there is enough depth.
All you need is a little imagination. You can also use your creativity when choosing containers. Bricks, cement blocks and wood are some things you can use to create containers for your vegetables.