I'm in a similar position. I currently have only my container gardens, however I help with my parents place in return for some of the produce. The best tips I have come up with are as follows:
1. Sneaky composting; place your
compost in a large pot half way up, cover with dirt, plant. This is my way of getting around otherwise restrictive rules.
2. Cycle your dirt. This works best if done in combo with tip 1. This allows the nutrients to stay balanced with out the need for fertilizer. When your done with one season of annuals, just mix all the dirt together.
3. Policultures and layers help. I was gone for a week this year during a heat wave... I lost most my plants and all my strawberries (hierloom) but one. That strawberry was in my poly 5 pot, all the plants in that pot survived. As for the layers, the vertical is your friend.