One of the most important requirements for grape growing is the right foundation. Grapes require quick, complete drainage around their roots, and won't grow in standing water. The best soil for grapes is a mix of natural soil and porous soil, with organic compost mixed in for long-lasting nutrition.
According to Ohio State University, the best fertilizer for grapes is balanced 10-10-10 fertilizer, which gives nutrition without altering the soil pH. The numbers indicate the percentages of nitrogen, phosphorus and potassium in the fertilizer.
Ohio State University recommends giving grapes 8 oz. of 10-10-10 fertilizer the week after planting. Gardeners should use granular fertilizer and spread it around the grapevine, 6 to 8 inches from the base. It's important to water immediately after fertilizer applications, to incorporate the fertilizer into the soil.
Gardeners should feed their grapes in early spring every year, a month before new growth begins. This early feeding encourages new growth and gives the vines the resources they require for blooming and bearing fruit.