With my garden planted and growing, I had to figure other ways to utilize my small space. The majority of my vegetables are in pots, so don't think you can't grow vegetables in pots. There are many varieties, even tomatoes, that you can grow in a pot, just be sure to have one that is large enough. Tomatoes, eggplant, peppers (of all sorts), cucumbers, zucchini, and green beans are all in pots in my garden.
This year I decided to grow cantaloupe, honeydew and watermelon which happen to be vine plants that grow horizontally. So I needed to come up with a vertical option - a trellis. This also required a watermelon variety that produces smaller, personal size melons. And to utilize my space I planted all three melons, with some space apart, in the ground with a trellis (that has some netting attached) behind them that can lean on a wall. The netting and wall should add enough support to help hold the weight of each melon and provide staking for the vines to grow vertically.
The second vertical garden idea is staking my cucumbers and green beans. To cut cost I found a trellis netting to hang along the fence so that I can space some of the cucumbers and green beans using the same netting. For the rest of the cucumbers, I made a tepee with wooden stakes, using twine to tie them together. This tepee is a little different than most you see pictured in gardening books. My Mother drilled holes in each stake (in the same spots) and then strung the twine through. The concept will be a tepee that has support for the cucumber vines to climb, but when the season ends will fold compactly for storage.