Grapevines require a lot of maintenance. Year on year, pruning is required to keep the vines free of tangles and to promote the most healthy wood growth. Without regular pruning, fruit production will be inhibited and new growth will be nonexistent. Over time, soil will require rejuvenation with compost or humus. Even old vines that look dead can be revived with the right kind of care.
Test the nutrient content of the soil under the vines using a pH test, available at local gardening centers. Take several soil samples from along the grapevine path and test according to the instruction on the test. A soil pH reading of 7.0 or above means the soil is alkaline, while 7.0 and below means the soil is acidic. Add lime to the soil to raise the pH or sulfur to lower the pH to the recommended level for your grapevine variety.
Locate the healthy vines of the plant, which will have a thick central trunk as well as two cordons, or horizontal vines extending from the top of the central trunk.
Prune long vines that are far away from the healthy, main trunk. These are old growth vines that take nutrients away from the healthy trunk.
Remove any dead, broken or diseased vines from the plant including the cordons and the branches, as disease will spread through these areas.
Find green or new cordons if there are any left on the old vine and trim away older cordons to promote the newest cordons' growth.