A garden bed can be created at no cost. It will take a little time. It could be improved with more time and some materials that are purchased. It is a doable project. Two required materials for a simple garden bed are newspapers and fallen leaves. Cardboard from an appliance box could be substituted for the newspapers.
A location that gets at least 6 hours of sun a day and does not have standing water is required. The width of the bed should be 3-4 feet. Reaching to the center of the bed while not stepping in it is the idea. A layer of newspaper 4-5 pages thick should be put down and covered with 3-4 inches of leaves. That is a minimalist bed which could be used for transplants when the time comes. The layer of newspapers and grass will smother most existing grass and weeds.
This bed design has limits and could be improved. One limit refers to most, not all, existing grass and weeds being smothered. Bermuda grass, which is common in the Chattanooga area, will grow through the mulch of newspaper and leaves. Getting rid of Bermuda grass without chemicals requires significant effort. Another consideration is past use of the plot for the bed. If it is on a former industrial site there is a possibility of chemical or heavy metal pollution. Edible plants are capable of absorbing toxins. One reason for gardening is to get healthy food so knowing the history of a plot is important. Container gardening is sometimes a better option, depending on the plot.
So finding a plot without standing water, Bermuda grass, and pollutants that gets enough sunshine are requirements for success. Improving the simple newspaper and leaves bed is then an option. Spreading lime which is available at garden centers before laying the newspaper will benefit most area soils. Attracting earthworms by spreading a little cornmeal before laying the newspaper is also beneficial. A one inch layer of compost over the newspaper before the leaves or instead of the leaves will help plants thrive.
This is a method for creating a bed that can be done without digging. It can be done in mid winter. If planning to plant seeds in the spring, using weed free compost instead of leaves is the way to go. More information about this method can be found by researching lasagna gardening.