Healthy soil is a critical component of any successful garden. Soil needs air and water to function, and compaction from foot traffic robs it of both. Raised beds are a good idea for sites with clay soil or areas with poor drainage. This makes them ideal for Georgia.
A rule of thumb is to fill the raised planting bed with sixty percent topsoil, thirty percent of an organic matter such as compost and ten percent Miracle Gro Organic (or a comparable product). Mix some sand throughout for drainage. It actually requires a lot of soil to fill a raised bed, but it is a worthwhile investment. You will reap the benefits in a more productive garden. Determine the cubic measurement of your bed to determine how much you need: width x length x depth. Those new to raised bed gardening will find it simpler to purchase in bags from a hardware store or feed store. For a 3x6 raised bed, I would recommend starting with ten 40lb bags of topsoil (about $12), one 48 lb bag of Miracle Gro Organic ($8), two bags of mushroom compost (about $9), and two bags of peat moss (about $10). This will make your soil start-up costs around $40. If you are composting already, mix it in as well. This might seem like alot, but remember that next year you will use the same soil, only needing to amend it with our own compost, a bag of topsoil, peat moss, and mushroom compost to replace lost nutrients. You would also save by not buying organic soil, but it is my preference when growing my food. You might also find a savings by buying in bulk. This might be a good option if you are developing several beds or have neighbors doing the same.
Please don't try to go a cheaper route by filling with dirt from your own yard. The weeds will show up in your bed and the soil will not produce the same amount or quality of food. When you realize that you will not be tilling and weeding, it doesn't seem like such a large investment. It really does pay off.
Backyard garden and chicken consultations are $60 in the Metro Atlanta counties of Gwinnett, Fulton, DeKalb, Rockdale and Henry. We are willing to travel outside of these areas for an additional travel fee.