Tomatoes are prolific growers in the garden and can produce significant harvests when given the proper conditions. Chief among their requirements is quality planting soil. Tomatoes need nutrient-rich, acidic soil with a high organic content, moisture-holding capability and easy drainage to allow excess water to escape. There is no substitute for a rich planting soil and a well-prepared planting bed and the quality of the soil will show in the quality of your tomato harvest.
Tomatoes require mildly acidic planting soil hovering between 6.2 and 6.8 pH. Soil that is neutral or alkaline and above 6.8 pH should be amended with elemental sulfur or iron sulfate to increase the acidity or lower the pH. Soil that is very acidic below 6.2 can be amended with hydrated lime to raise the pH to within the desired range.
Rich in Organic Material
Tomatoes grow best in moist and nutrient rich soil. Significant levels of organic matter are required to both feed the roots and hold the captured moisture. Amend average and poor soils with generous amounts of compost and aged livestock manure up to 7.5 tons for every half acre of tomato plantings. Cover crops can be tilled under in large scale production to add to the nutrient content of the soil. Chemical fertilizers cannot compensate for nutrient-poor soil when growing tomatoes; the salts from large amounts of fertilizer build up and inhibit plant performance.
Deep Soil With Light Texture
Tomatoes need deeply tilled, loose and light soil that roots can quickly and easily penetrate. Light loamy soils also allow excess water to percolate through the soil and prevent the pooling that can cause root and stem rot. Planting beds should be tilled or dug and turned to a depth of a foot at minimum. Clay soils should be lightened up with generous amounts of organic matter and sharp sand to aid in lightness and easy drainage.