Quick and easy examples. These are all subject to your mentioned home raids, absolutely, but I'll be killed in a raid of my home and then the garden won't matter:
1 - Grow Boxes, Homemade Worm Castings, and Lights - these start my garden every year in my garage. Some of the fruits/veggies remain in the boxes, some are transplanted. At the end of the season the produce in the boxes is moved into my garage and back under lights to continue producing as long as possible. I have T-5 lights which produce minimal heat and draw minimal electricity while giving higher luminous efficacy (lumens per Watt used). This year they have been connected to small solar panels - this would not continue to be useful in your scenario as the solar panels would be highly visible. And a worm farm - if you don't have one I highly recommend one.
2 - Hydroponics - purely for the growth rate which can be 40% faster than soil gardening because nutrients are more readily available to the plant. Using the same lights mentioned above, this is doable indoors, subject to a home raid, but quietly sustainable using expanded shale or loose clay for growing mediums and knowledge about the nutrients plants require.
3 - Companion Planting - use the current shrubbery around your house and in your neighborhood to "hide" your produce. Plant "Three Sisters" style - worked for the Native Americans terrifically. My corn, beans, and squash have no problems growing up against my Russian Olive and Pyracantha hedges.
4 - Permaculture - what the gov't doesn't understand is food will not be confiscated. That's just my hedge that happens to berry throughout the year; those are just weeds growing near the pond; the mushrooms on my spruce trees? they're not edible; those bushy things that look like celery, they're so pretty; etc.
Of course, none of this is possible without knowledge. Gardening teaches me something every year. It's not something you'll be able to open a packet of seeds and magically do when you absolutely need to. Knowledge - before god, guns, gold, or seeds.
edit on 4/5/2013 by Halekoch because: Forgot Permaculture