Start a compost pile as far in advance as you can for the garden. Poke 1/2-inch holes around a 30-gallon trash can and set on bricks. Pour all the kitchen wastes, such as leftover vegetables, fruits, egg shells and coffee grounds, into the can, along with a shovel full of dirt or tree leaves each time you add something. Keep a concrete block on the lid to prevent neighborhood animals from getting in. Two weeks before planting the garden take the material from the garbage can and dig it into the soil where the garden is to be. Continue to keep the compost going so that you can add it to the soil after the garden ends. Nothing you can do will improve the soil as much as this.
Place the garden where the plants will receive the maximum amount of sunlight. Both poor soil and a lack of sunlight are discouragements to plant growth, but if you can have at least good sunlight, it makes up for some of the lack of a good soil.
Discourage soil pests by keeping all your gardening tools clean. Do not dig in one spot and then dig in another with the same dirty tool. That carries infections from one spot to another.
Dig all-purpose fertilizer into the soil before planting the garden. When the plants begin to set flowers, add a spoonful of fertilizer a few inches along side each plant stem.
Water the garden on a consistent basis. If the soil is dry to the touch 3 inches below the surface, then give it at least enough water so that the soil feels wet 6 inches below the surface. If the soil seems to be heavy and feels like clay when you hold it, then break the watering into two separate times. If the soil seems to be very crumbly like sand, then water more often.
Add bags of topsoil, manure or compost from the store if you can. Work the new material into the top few inches of the existing soil.