LAWNS TO GARDENS
Broccoli plants mulched with scalped lawngrass,
growing where the lawn used to be...
STEP 1: THINK ABOUT THE PROJECT
First of all, is the soil beneath your lawn acceptable for growing things? Unless your soil has been thoroughly poisoned with industrial waste or some other long-lived contaminant, surely it is. Usually the contaminants of most concern are lead, arsenic and asbestos. Most lawn pesticides are designed to break down fairly quickly. Read more about gardening in lead-contaminated soil here. If your soil is too polluted, you can use a "raised bed system," bringing in your soil or other growing medium from elsewhere. A good place to learn more about chemical-free gardening is at Organicgardening.com.
Remember that one form of gardening, hydroponics, doesn't even use soil. Hydroponics proves that there's nothing magical about soil. (More info on hydroponics here.) Even if the soil is rocky, so hard that it's brittle, or full of trash, you can grow things in it. However, if it contains broken glass or other sharp objects, it might be dangerous for you to work the soil with your hands.
If your soil is poor, it can be improved in a number of ways, though it may take several years to do so. Still, even poor soil, when properly managed, can grow things.
Therefore, unless your lawn soil is full of dangerous contaminants or objects that can cut you, there's no reason for you not to convert your lawn to garden, but many reasons for you to do so.
STEP 2: SCALP THE SOD AWAY
Use a hoe as shown at the right, working backwards, scalping where you've just been. As you move across an area, the sod balls up between you and the hoe so periodically pick up the loose material and carry it away. Unless it's full of weed seeds, use it as mulch or compost it.
At the left notice how one corner of the hoe's blade is brought toward you, not the blade's flat bottom. Somehow this helps the blade cut grass roots and move through the soil. Here's the main secret in scalping sod with a hoe: Keep your hoe's blade sharp! After every hour or so you should file your blade's head to a fine sharpness. Cut deeply enough to remove sprout-forming rhizomes of such things as crabgrass, but don't remove too much dirt.
STEP 3: SPADE THE SOIL
Once again, work backwards, spading the soil you've just stood on. Also, once again, the work goes much, much easier if you keep your blade sharp.
All that chopping and spading may seem like an awful lot of work, and it is. However, if you do just a few minutes each day, day after day, you'll be surprised how large a garden spot you have after a week of work.