Pensacola News Journal

for: Sunday, Jan. 28, 2000

by: Daniel E. Mullins

Extension Horticultural Agent

Santa Rosa County

Prune Grape Vines for Maximum Yield

Many homeowners include a planting of grapes within the landscape and this is the time of year that pruning concerns arise. I have received numerous questions on the subject over the past couple of weeks. Here is a sampling.

Q. Should grape vines be pruned every year?

A. Yes, grapes develop much vegetative growth over a single growing season and, if allowed to go unpruned, the vines tend to become crowded and production is reduced as a result.

Q. When is the best time to prune grapes?

A. Anytime from January until mid-March is an acceptable time.

Q. Every time that I have pruned my grapes, sap flows from them. Will this harm or kill the vines.

A. In grape pruning language, the loss of sap from freshly pruned vines is known as “bleeding.” It is not harmful if pruning is done when the plants are in a dormant condition.

Q. I become confused, even bewildered, when faced with pruning grapes. There is usually so much growth to deal with. How can I decide what parts to cut off and what to leave?

A. The southern grapes, or muscadines, are pruned to a spur system with permanent arms. Assuming that you have the most commonly used two wire trellis setup, I suggest the following:

First, locate the most vigorous main branch running in each direction on the wire. On a two wire system this would mean that there is a main trunk with a total of four branches - two running in opposite directions. Next, prune out all other large canes by tracing back to the trunk and removing them.

You will be left with these four main branches with many smaller branches growing from them at approximately a ninety degree angle. Now, here is where many people make a mistake that costs a year’s worth of fruit. These side shoots should be pruned back, but not all the way to the main cane. When cutting, leave “spurs,” or short pieces of stem containing at least two buds.

When the job is properly finished, each vine will appear as a skeleton of its former self. There will be one major branch per wire, with short stubs of one to two inches in length where each side branch occurred.

The short pieces that are left are a portion of last years growth, and the buds that sprout will form the fruiting branches for the upcoming year. A word of warning: If the side shoots are pruned all the way back to the main canes, all of next year’s fruiting wood will be removed and you will not have grapes for 2 years!

Q. If I prune my grapes in mid-winter, would I be making them susceptible to cold damage.

A. No, grapes are very cold tolerant.

Q. Should I use pruning compound or wound dressing material on the cut surfaces.

A. No, cut surfaces will heal quickly once spring growth begins. Pruned grape vines usually bleed in our area, regardless of the time of year that cuts are made and the flowing sap is under pressure. It would simply push its way through, or around, any compound that is applied.

Question of the week: My sago palms have suffered from cold injury this winter. Should I start removing the dead fronds, or wait until spring?

Answer: Sagos have indeed suffered from the extended cold periods. Hold off on pruning until late winter or early spring. At that time remove any fronds that are totally brown, but leave those that have green on half or more of their surface area. This allows some photosynthesis to continue while the plants are recovering. The older, damaged fronds can be gradually removed next season.