In Suburbia, a homeowner is blessed with sometimes a full quarter acre of land to raise food on. In the city, a homeowner is lucky to have a nice driveway.
Driveways can be excellent places to grow food. You do not even need to tear out the concrete! Simply construct a bed on top of it, and fill it with dirt.
1. Build the walls. The walls of the bed can be almost any material. Wood, concrete blocks... even old tires or recycled chunks of concrete (free from many construction sites if you ask) work wonderfully. Just make sure that the wall retains soil more than four inches deep, and ideally more than eight inches. The deeper the bed, the better: two feet is best. But, if all you can do is four inches of soil, that will work in a pinch. Your wall need not be "water tight." You shouldn't be watering you soil so much that water is pouring out the sides, anyway! It just needs to be able to hold back the soil.
2. Terrace. Most driveways are sloped. This is a problem, as you will encounter erosion almost immediately. After building the wall around the driveway, you will want to terrace the slope. Construct more walls on the inside of the bed perpendicular to the slope so that you can have several level beds to work with.
3. Plan irrigation. You need not have a very fancy irrigation system. A $5 sprinkler purchased at a hardware store and a 100' length of hose is probably all you'll need (hose length will vary, depending on the length of your driveway and the distance to the spigot). A timer to turn the water on and off for you while you're at work or school might also be helpful. If you want to get creative, set up several sprinklers on several hoses so that, with the help of several timers, you can have your entire garden watered during the same day. If you want it simple, have one hose and one sprinkler, and move it about wherever your garden needs water.
4. Fill with soil. While any soil will do, select one with a lot of clay in it if you can. Until you've fixed up the soil using Coastalfields' method of Active Fallow, the clay will help retain water and protect your plants. Soil can be expensive if purchased, but may also be cheaply acquired either from a construction site (they usually pay to have the dirt dug up for foundations of houses or in the construction of highways hauled away) or else from a wholesaler. Call around to find the best price.
5. Protect your walls. Plant bushes to shade your walls: if you don't insulate your walls, the area nearest to the walls will always be the driest and least productive. These bushes can be fruitful (prickly pear or raspberries are great) or ornamental (roses provide beautiful flowers and nice fruits, too).
6. Plant your food. Figure out what you want to grow, and why: are you going to try to feed yourself? Potatoes offer the most calories per square foot or dollar of seed, but maybe you want more leafy greens. Maybe you want fruits? Contact Coastalfields if you have questions on how to select what things to plant.
7. Practice Active Fallow. Let the weeds grow, till before planting (without killing keystone individuals-those plants and animals that are relied upon by many other plants and animals for shelter, food or other resource needs), after you harvest (again, watching for keystone individuals), and - if your driveway garden is large enough to need an aisle - in the aisles as often as you can. Tilling in the aisles every day is not too often. For tillage, we recommend a shovel.
But what do you do with the garage and the car?
The garage can now be used as almost anything. If you leave enough space for your car to go up the driveway, you can park your car there. If not, transform it into an indoor gym so you can stay fit in the winter, or a nice library. A workshop to practice your crafts, or to build nice chairs or tables to sell for extra income. Purchase grow lights and a heater and you can garden inside all winter long!
As for the car? If didn't leave room to park in the garage, and you don't want to consider giving it up (consider the savings in car payments, insurance, gasoline, repairs, etc...not to mention the ability to read a nice book while riding the bus), you can usually park it on the street without any problem whatsoever. Or around the block. Or in your neighbor's driveway (offer them some of your nice food in exchange-they'll love the trade!).
Gardening on a driveway improves your home's value, providing a beautiful landscape (especially if you plant it in no-hassle xeric flowers before selling your house) and a fantastic way to eat better, cheaper and more nutritiously...while enjoying quality time with your family, friends and neighbors.