Concord grapes are a popular grape for the home grower as they can be used both as a table grape or pressed to make juice. It is the most widely planted grape east of the Rockies and is very hardy. Knowing how to prune your grapes is the secret to getting lots of grapes. Vines must be pruned severely and methodically for the best yield. Without pruning, grapes can quickly become tangled messes with very little fruit.
Prune in late winter when the vines are dormant. Do not prune during periods of severe frost or after the sap starts to rise. Only prune last year's growth as grapes grow on the current growth from last year's wood.
Find the old wood. It is easily recognizable because it is coarse. From the tip of the new growth, follow the vine back until you reach the coarser bark.
From the old growth, come forward four or five buds and cut the vine with the pruning shears.
Prune again in the spring. After the new leaves are fully developed in the spring, you can prune again. Remove all the weak or thin shoots, leaving only the strongest.
Prune again in summer. After the vines have fruited, prune shoots back to the third or fourth leaf. Leave the shoots that have grapes on them. Cut out new growth and remove leaves that are shading growing fruit clusters so that the fruit gets as much sun as possible while growing.