These days, tilling dirt is a matter of personal choice. There are some people in the world of gardening who believe that you should be tilling your soil at least once, maybe twice a year. There are others who believe that tilling your soil at all can be harmful to your soil in the long term. For the purposes of this article, we are assuming that you wish to know how to till a garden on a yearly basis.
Before you can learn how to till a garden, you need to know when to till a garden. For most people, the best time for tilling dirt is in the spring. Before tilling your soil, you must wait for two things: the soil must be dry enough and warm enough. If you don’t wait for these two things, you may be causing more harm than good to your soil and plants. To see if your soil is dry enough, pick up a handful and squeeze it. If the ball of soil in your hand falls apart when poked, the soil is dry enough. If it stays together in a ball, the soil is too wet for tilling.
To see if the soil is warm enough, stick your hand or a finger a few inches down into the soil. If you are unable to keep your hand or finger in the soil for a full minute, than the soil is not warm enough. You can also simply measure the soil temperature . You need the soil to be at least 60 F. (15 C.) before tilling and planting.
After you have determined when to till a garden, you can start tilling the dirt. Mark out the area where you will be tilling your soil. Start at one end of the marked out area with your tiller. Much like you would when you are mowing the lawn, go across the soil one row at a time.
Slowly make your rows. Do not rush tilling your soil.You will only be tilling the dirt in each row one time. Do not go back over a row. Excessive tilling can compact the soil  rather than break it up. If you plan on planting cool weather crops (like lettuce , peas  or cabbage ) next year, you will want to do some of your tilling the fall before. The soil will not be dry enough or warm enough to till in the early spring when these plants need to be put in the ground. Knowing when to till a garden and how to till a garden will help your garden grow better every year. taken from URL to article: http://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-till-a-garden-tilling-your-soil.htm
Till next time, this is Becky Litterer from Becky's Greenhouse, Dougherty Iowa