Nutrient Requirements for Grapevines

Analysis and Testing

• Some nutrients, such as phosphorus, may measure low in soil samples although the grapes have an adequate supply due to fungal relations in the plant itself. Grapes also have the ability to store nutrients in their plant leaves for future use. For this reason, nutrient levels should be monitored carefully by a combination of soil pH testing, petiole analysis and leaf blade testing.

Common Nutrient Requirements

• Generally speaking, most grape growers should apply a nitrogen fertilizer to their grapes two weeks after planting and once a year in the spring. The University of Minnesota Extension recommends applying 1 lb. of 10-6-4 fertilizer per plant. You should ideally test soil, petioles and leaf blade before applying any nutrients, since over-application can result in slow growth and decreased crop yields.

Impact of Growing Region

• Keep in mind that nutrient requirements for grapevines may vary based on location. Some nutrients may be more commonly problematic for grape growers in certain regions. In Arizona, for example, nitrogen, phosphorus, potassium, boron, zinc and iron often pose problems for growers. In Iowa, on the other hand, nitrogen, potassium and zinc are the most common problem areas.