So you have weeds and grass, and you want flowers and vegetables? The first thing is to pick a site. It needs to get more than six hours of sun a day, drain well, and have access to water. Hauling water to a garden is no fun at all.
The next task is to kill the grass and weeds and get down to the dirt. There are three ways of doing this. The first is to dig out every bit of the weeds and grass. As you can imagine, this is very labor intensive and is rarely done.
The second way of killing the grass and weeds is to use herbicides. The precise herbicide depends on what you have growing. Glyphosate is a very broad spectrum herbicide and kills grass and most weeds. The trade name for glyphosate is Roundup.. Caution should be used and the label directions followed exactly.
The third method of killing the grass and weeds is to smother it with a tarp or plastic. While black plastic will kill the grass by starving it, spreading clear plastic over the grass during the summer will cook it and kill it faster. However, this method does take a month or two before everything is dead.
Once the grass and weeds are dead, you need to till the plot. It is acceptable to till the dead grass into the dirt. It will decompose and add organic matter to the dirt. Organic matter holds water and also helps keep the soil loose and aerated. Till the dirt to a depth of six inches so the roots of the vegetables can grow in loose soil.
To add nutrients to the soil, it is necessary to spread compost over the garden. Three inches of compost should be tilled into the loose soil. By the time you are done, the compost should be evenly spread throughout the six inches of tilled soil.
Finally, the soil is ready for the plants. There are just a couple of things left before you can plant. First, take a soil test and send it off to be analyzed. The County Extension Agent can provide bags and instructions, and the test is fairly inexpensive. You will get back information that will tell you what fertilizer you need to put down and in what quantity. Without a soil test, you will be just guessing and may well waste money putting down fertilizer you do not need, or putting down the wrong fertilizer.
The last thing is to provide for irrigation. There are several ways to do this. You can use one of the sprinklers that go back and forth over the plants and water them. However, in the summer, up to 40% of the water evaporates before it ever reaches the plants. That is a lot of water to pay for when it never reaches your plants.
A soaker hose is a better alternative. It dribbles water out right at ground level. However, a drip irrigation system will deliver water to the roots of the plant and can be controlled by a timer. That means that it will come on at a set time without you having to turn it on. Most irrigation timers now have rain sensors, too, so that they do not come on if the garden gets rain.
When you finish with your water system, this is what you have. This plot is ready to plant.