As you can see, I've still got a bit of my winter lettuce still growing, and I have an established rosemary bush . I've planted nearly all of the other barrels, except for 2, which I need to pick up more seeds for. These barrels are on the east side of the house, so I plant the tomatoes on the west side for more sun. The barrels get plenty of sun until early afternoon, so nothing gets scorched in the hot Brentwood summer sun. And the tomatoes get lots of hot sun on the other side. I'm planting sugar peas and green beans along the back fence (to the south), with little marigolds in front of them.
I also give all of my plants a healthy dose of Miracle Grow every so often. The barrel garden looks great all year long, so the yard doesn't look shabby at all. The garden is about 6 years old.