Grapevines require drastic pruning annually to keep them in check. Vines that are not sufficiently pruned are more prone to disease, and the grapes produced don't taste as good because they're shaded by the overactive vine. Table grapes are better for eating fresh that for wine making, and include varieties like Flame seedless, Reliance and Thomson seedless. They may have green or red skin. Prune vines of table grapes while the plants are still dormant, late in winter or early in spring.
Inspect your grapevine for dead or diseased canes. Dead canes will be tan or brown and appear hardened. Diseased canes may be discolored, wounded, scarred or otherwise appear different than the healthy canes and must be removed to protect the health of the grapevine.
Clip off dead or diseased canes with your pruners, cutting them off at the base. In between each cut, sanitize your pruners with disinfectant spray. Discard all clippings when you've finished.
Cut off every other cane that grew the previous season, removing it at the base (the remaining canes will bear fruit this year). If you left every cane, the vine would grow out of control and become a tangled mess. This thinning promotes plant health.
Prune the remaining canes, leaving only two buds. This will promote new growth to keep your grapevine productive.
Trim any growth that rises above the training system of your grapevine or any tendrils that wind around the vine, since they can suffocate canes. Also cut off suckers that grow from the vine's trunk.