How to Care for 30 Year Old Concord Grape Vines in Indiana

Prune the grapevine when it is dormant. If it has not been well pruned for much of its 30 years, this may prove difficult. You do not need to attempt to prune into a traditional cane-trained or cordon-trained system; that is most effectively done during the first two years of growth. For a 30-year-old vine, concentrate on removing as much shade as possible over the fruit, since more sunlight to the grapes means sweeter fruit.

Check the grapevine's leaves for disease and pests. If you see red dots on the leaves or brown grapes, you may have have a fungus and need to apply fungicide to prevent spreading. If an old grapevine has not been well pruned, chances for fungus caused by a lack of air circulation increase. Spray a fruit and vegetable fungicide, such as Captan, until the affected and surrounding areas are well covered. Don't use fungicide with sulfur when the temperature is 85 degrees Fahrenheit or higher.

Apply 1 1/2 lbs. of 10-10-10 fertilizer approximately a month before new growth appears. Spread the fertilizer evenly under the grapevine, and do not apply it fewer than 6 inches from the base.

Remove all weeds within 2 feet of either side of the vine. Mulch this area after weeding to prevent more weeds from growing, and do not disturb the trunks or roots when weeding. If the area has not been well weeded for 30 years, the weeding may be extensive.