Plant Food for Concord Grape Vines

Fundamentals

• Concord grapes produce about 20 lbs. of fruit per vine per year, according to the Ohio State University Extension Service website. Vines remain productive for more than 40 years if soil fertility is properly maintained.

  Improving soil health provides benefits to grape vines year after year, according to Spectrum Analytic Inc. Agronomic Library website. While improvements to the grape crop may not be noticeable the first year after fertilizing, the following years will produce increasingly dense clusters of grapes and steadily growing vines.

Preparation

• Periodic analysis of soil samples can determine what nutrients grape vines need in a specific area and thus determine the type of fertilizer that should be added, according to Spectrum Analytic Inc. Because grape vines grow deep roots, soil samples should be taken from a deep level and not just from the surface. Professional leaf analysis provides additional information about a plant's nutrient needs.

Fertilizer Application

• Grapes grow best in soil with a pH between 5.0 and 6.0, according to the Ohio State University Extension Service website. Apply lime to adjust the pH only if a soil test indicates a need.

  As a general rule, 8 oz. of fertilizer with a 10-10-10 ratio of nitrogen, phosphorous and potassium should be applied seven days after a vine is planted, according to the Ohio State University Extension Service website. In the second year, the amount should increase to 1 lb. per vine. Fertilizer amounts for the third and subsequent years should be 1 1/2 lbs. per vine, applied about 30 days after new growth appears in the spring.

  Grapes of all varieties inefficiently absorb potassium from soils, making the nutrient one of the most important fertilizer elements for growing grapes, according to the Spectrum Analytic Inc. Nitrogen requirements are not high in grapes and the addition of nitrogen to soil late in the growing season can damage the plant.

Considerations

• Fertilizer should be mixed at least 2 inches deep into the soil to promote root absorption and to reduce runoff in heavy rains, according to the University of Missouri Extension Service.

  Fertilizer should not be concentrated around the base of the vine. It should be dispersed evenly under the spread of the vine, starting at 12 inches from the trunk and moving outward, according to the Ohio State University Extension Service website.

  Grapes can tolerate a variety of soil types, but require good drainage, according to the University of Missouri Extension Service. While grapes for arbors or trellises grow densely together, the plants prefer locations with full sun exposure.

Cultivation

• Grape vines should be planted in early spring after soil is sampled and amended, if necessary. Broken or dead portions of branches and roots should be pruned, as should top growth, so that the plant is a single cane that can be tied to a stake to keep it off the ground. Mulch helps keep weed, insect and disease infestations to a minimum.