How to Manage Pests

Pests in Gardens and Landscapes

Grape Fertilization Guide

Adequate nutrition is important for high-quality grapes. Avoid excessive fertilization and rich soil, however, because they will contribute to excessive vine vigor and may reduce fruit set or fruit quality or both. This table serves as a guide only; fertilizer may rarely be needed in some aeras with rich soil.

Element needed Fertilizer Amount per vine When to apply Comments
Ammonium sulfate
1 lb
Berry set stage or following bloom
Berry set occurs when berries reach 0.25 inch diameter
Ammonium nitrate
0.75 lb
0.5 lb
Mixed fertilizers
Follow label
Animal manures: poultry, rabbit, steer, cow
5 to 10 lb
15 to 20 lb
January or February
Poultry manure may cause zinc deficiency in light, sandy soils
Basic or neutral
Zinc sulfate
(52% zinc)
0.1 lb/gal
1 week prior to bloom or at full bloom on foliage
Don't apply after bloom
Potassium to compensiate for deficiency
Potassium sulfate
(44% K)

Severe: 5 to 6 lb/vine
Moderate: 4 lb/vine
Mild: 3 lb/vine

When deficient, apply to soil 6 inches deep, 18 inches from trunk
Concentrate at vine
irrigate after application

Statewide IPM Program, Agriculture and Natural Resources, University of California
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