Whether you plant vegetables or perennial flowers, proper soil preparation is vital if the garden is to thrive. While every plant variety has different soil needs, most plants generally require soils that drain well, are rich in organic matter and that supply some form of nutrients to the plants' roots. Soils must also be relatively weed-free, as weed plants can quickly overtake young vegetables or flowers in an otherwise healthy soil bed. Prepare the soil the fall before planting, when possible, otherwise do soil prep in spring before the first seeds and seedlings go outside.
Pull all the weeds from the area and dispose of them. Remove the weed roots as well as the foliage, otherwise the weeds will grow back from the root pieces.
Perform a soil test on the bed. You can buy soil tests at garden centers or have your county extension office do a test. Take a sample of soil as directed on the test instructions. Follow further test instructions for processing the sample or return it to the extension office for processing.
Adjust the acidity, or pH, of the soil as directed by the soil test. Most vegetables and flowers prefer a soil pH between 6.0 and 6.5. Raise soil pH by adding agricultural lime at the rate recommended on the test. Lower pH by working sulfur into the soil at the recommended rate.
Loosen the top 12 inches of soil in the bed with a spade or power tiller. Cover the bed with a 2- to 4-inch layer of mature compost and work this into the loosened soil. Compost aids drainage while adding organic matter to the soil bed.
Fertilize the soil bed before planting. Apply 2 lbs. of 5-10-5 or 6-12-12 fertilizer per 100 square feet of soil bed. Work the fertilizer into the top 6 to 8 inches of soil. Apply fertilizers in the spring three or four days before planting the bed.