Before you start, you should realize that you will always have some winter kill at the tips of the canes. No shoot ever completely hardens to the tip. Therefore, a few inches will be green and growing when the onset of winter begins. Expect this portion to winter kill. That said, you should realize that the buds near the tip usually don't form primary, fruiting buds and we will prune them off routinely anyway.

Begin by starting at the tip and prune back towards the base of the cane one bud at a time until green wood is found. Take note of the color of the green. It should be a fresh and lively green, even if it looks dry. Dull green or olive green usually indicates damage. Portions with these colors will usually die as the vine comes to life later in the spring. Sometimes you will find buds pushing from these sections that will wither and die later.

Cut a cross-section through the first bud found arising from fresh, green wood with a sharp razor blade. Grape buds are compound buds and usually consist of three internal buds. A primary bud which may contain the beginning of the inflorescence and will bear the fruit for this year, a secondary bud, and a tertiary bud. It is the primary bud that is the most sensitive to winter kill with the secondary and then the tertiary buds being more hardy. If the primary bud is killed, some varieties will set a small crop from the secondary bud. The tertiary bud is almost always vegetative. Hopefully, you will find all three alive with a bright green color. Any discoloration will indicate damage.

If the primary bud is found dead, keep sampling until a good primary is found. This will give you an indication of how much damage was suffered over the winter. Some vineyardists count the number of buds from the base of the cane to where the tip winter killed and determine a percentage of winter kill from the number of buds sampled that showed discoloration or necrosis.

Using a magnifier or binocular stereoscope, you can then examine the primary bud closely for miniature flower clusters. Finding them will indicate that you will have fruit in the coming growing season. Some vineyardists cut longitudinally through the bud to determine this. Yield estimates can be made based on this assessment.

An alternative method is to take a section of the cane and place the cutting in a glass of water at room temperature. In a few days the buds will begin to push and you will be able to visually see whether the primary, secondary, or tertiary bud is alive. Once the new shoot is elongating, clusters will be seen if they are contained within the bud.

Pruning can begin once you have an idea of which buds are alive and whether they are fruitful If you are spur pruning, only the basal buds need to be alive and fruitful. But winter kill assessment is needed for cane pruning to determine how long you may prune to leave only fruitful buds. I have found that if you cane prune to 10 buds and the last two buds are alive but not fruitful, you run the risk of having the two tip buds produce vegetative shoots that out grow the fruitful buds and deprive them of good growth. Situations like this also make the vine unbalanced and harder to prune in the coming season.

This workshop will cover Bud Evaluation, Trellis and Training Systems, and basic Spur and Cane Pruning. We will also have some discussions of varieties and other topics of interest to the participants such as the use of sodium alginate for delaying bud burst and frost avoidance. Other methods of frost avoidance will also be discussed. It will be a half-day workshop at the Rist Canyon Vineyards just to the northwest of Fort Collins, CO.

I have tenatively set the date for Sunday April 18, 2004. (In the event of deep snow on that date, I will re-schedule the event for the following Sunday.) Rist Canyon Vineyards is located on a dirt road and 4-wheel drive vehicles are recommended for travel.

If you would like to attend, fill out the form below to obtain the times, adgenda, and a map to the Rist Canyon Vineyards.