If you're renting and don't want to go to the expense of putting in raised beds, consider a child's 3' wading pool as a potential gardening source.
One child's wading pool costs about $8-$12 (depends on where you buy it), and can grow enough fresh food for salads and meals for one person - or supplement store bought for 2 - for an entire growing season. And if you have a grow light and space indoors, you can grow all year around.
Let me show you.
This is enough soil and mulch for 1 wading pool.
For outdoor use, cut drain holes all around the pool:
Then line the pool(s) with weed cloth - this keeps the soil from seeping out of the drain holes, and fill with the soil.
This is very important: place the pools where you want them to be. Once filled with soil they will be too heavy to move. The only way to move them then will be to shovel all the soil out. Make sure your pool(s) are exactly where you want them to be. Leave enough room to fit a lawn mower between them!
This is one pool partly filled:
This is one pool planted with tomatoes, bell peppers, and bee balm plants and seeds for carrots, radishes, cucumber, and peas.
Here I have 2 pools filled, planted, and seeded:
Here they are mulched and with climbing supports put in (and Itzl):
These 2 pools produced, over the course of the summer, enough carrots, radishes, peas, tomatoes, lettuces, cucumbers, basil, parsley, dill, bee balm, and blue lake green beans that I didn't have to shop for any of that the whole summer for my family of 3 (the rest had grown up and moved out).
I don't have pictures of it, but I added 2 more pools the next year and grew potatoes in one (enough potatoes to last the entire year!), and enough tomatoes, carrots, peas, green beans, onions, and herbs to put up for the entire year. The cucumbers, radishes, and lettuces lasted the entire growing season. These 4 pools fed a family of three quite nicely.
I've also grown enough rice in a wading pool to produce all the rice a family of three needed who didn't rely on rice as their main starch.
And I've grown enough wheat in three wading pools to produce enough wheat to make bread for a family of three for most of a year (4 pools would have been enough to have bread and seed for the following year).
I've been growing in these pools now for 6 years, and they remain weed free with minor vigilance. I add compost once a month during the growing season. Since I have a worm bin, I also add worm castings in the spring and as I harvest the castings.
When I sell this house and move, I want to put in a keyhole garden.