Time of Year to Prune Grapes

Light Pruning

• Light pruning, or pruning that does not involve cutting any mature vine, can be done at any part of the season. Cutting back new shoots and tendrils that are venturing onto your neighbor's fence will not damage your vine, as long as you do not cut into the mature, woody portion of the vine. You can imagine the thin green vines as scouts for the plant: they are constructed in such a way that if they are snapped off or clipped, they do not cause damage to the plant itself.

Medium Pruning

• Medium pruning means pruning mostly green shoots and a few mature vines. This type of pruning is best done from the middle of the season forward, typically mid July through the end of the season. The mature wood of a grape vine is porous and resembles a cluster of small straws held together by the bark. Through these straws flows water and nutrients throughout much of the season. Any cut or break in the mature woody vine will result in a slow drip from the vine, essentially bleeding the vine of moisture and food. The later you can wait to prune, the less water and food will be flowing through the vine.

Heavy Pruning

• Heavy pruning is pruning that will be mostly done on the woody mature vine. This type of pruning is necessary when a vine has been allowed to grow unchecked for a number of years. Heavy pruning should only be done in the dormant season, the time after all of the leaves fall from the vine and before spring buds appear, usually January through early March. The vine will be dormant, meaning the vine will not have water and food flowing through it, and your pruning will do less damage and be less likely to kill the vine.

Fruit Pruning

• Some growers cultivate the vine for aesthetic purposes and do not use the fruit. Ripening grapes draw bees and animals, and growers who are not interested in harvesting the grapes will prune the fruit off of the vine before it matures. This job can safely be done throughout the season, by snipping the small clusters of grapes before they have a chance to mature.