“Natural abilities are like natural plants; they need pruning by study” – Red Auerbach
Have you ever squeezed your hands together incessantly for hours on end? Perhaps working out with one of those hand mechanisms to develop an iron grip or firm-handshaking your way down the road of politickin’; the muscles begin to cramp and your dominant hand is sore for days thereafter (not to mention the blisters). That is my best description of pruning. As glamour-less as this task is, it is a necessary evil for the development of the vine and eventual crop of grapes. Starting in the depths of winter and continuing throughout the calendar year as needed; pruning is the first step in crop management.
Pruning: Giving the vine a haircut; using sheers to clip old canes to control the number, position, and vigor of the next year’s shoots. As scary as it seems, it is not out of the question to clear out 80-90% of the previous year’s growth. Typically performed during the dormant season of November-March; depending on the weather (under 40 degrees doesn’t work well for me) and the status of buds.
Crop Management: This encompasses all activities throughout the calendar year pertaining to the care of the grapes. Pruning, fertilizing, spraying, watering, cluster thinning, shoot positioning, mowing, removing weeds, netting, and finally, harvesting. When I signed up, I thought you just put a seed into the ground during the spring and came back the following fall to find a tree bearing bottles of wine. Shoot.
Pruning is not only effective for making a vineyard look nice but is critical for vineyard functionality. If all the buds on a particular cane are left to grow to their desire, the crop will overproduce and the vintner will have an abundance of grapes devoid of the desired sugar/water/acid balance lending to a flabby wine searching for complexity and character. The following year will be equally frustrating when the vine has the appearance of a hedge bush and you don’t know whether you are looking at a cane from the previous year, a shoot for the coming year, or a family of squirrels that reckoned the monstrosity of a wood maze looked like a hospitable environment. Pruning is critical and as with everything else related to a vineyard, timing is of upmost importance.
In Missouri, pruning is a delicate balance of subjective judgment and crossing your fingers. Let me briefly take you back in time, to vineyards far far away in the land of April 2007. The picture below from a Missouri State climatologist portrays a scary picture of the nightmare that unfolded that spring:
This chart represents the “near-record period of warm weather, which caused grapevines to de-acclimate and begin growth, followed by a five-day period of record-breaking cold temperatures” – Missouri GWI
I include this because of the importance of the “Easter Freeze of ’07” and the lessons to be learned for growers in our climate. If an unusually warm period is experienced in January, February, or March, buds may begin to swell as the plant jumps the gun. A grower is then forced to make a decision:
- Prune it all! Treat it as if you were pruning in a typical year. This is the gung-ho risk taker’s approach- only needing to make one pass and whatever happens, happens. If there is a hard freeze (like Easter ’07), the entire crop is at risk of an early demise as the freeze decimates the remaining life on the plant. The vines will be pruned to the typical amount of buds per shoot (varietal specific) and the freeze will be a disaster as there are no secondary buds for natural insurance. Unfortunately, the largest producers typically have no choice but to complete all pruning during the winter months when time is most ample for them.
- Don’t prune a thing (delayed pruning). The conservative approach- fear in the back of the mind of impending freezes will keep the grower from pruning at all. If, for example, there are 15 buds on a given shoot that should be pruned back to 5, the vintner will let all 15 grow and the buds furthest out will break first. If a frost occurs, these will be the first to be damaged, and they will be pruned off once there is no longer a threat of frost, allowing the primary buds to swell and break. The primary risk in this approach is that you have to be careful when pruning this far into spring, because it is easy to knock off the primary buds that you worked so hard to save. Disrupting delicate buds is not an issue during dormancy. The problem in ’07 was that it was so atypical that most growers, even the conservative ones that delayed, had decided to prune believing that a hard freeze was out of the question.
- Prune most secondary buds but not all the way to the desired buds (double-prune). This method is for the grower with crazy amounts of time and energy that can be devoted to making two passes through the vineyard. The first pass will prune the furthest buds but leave some secondary. If a surprise frost kills some of the buds, these can be pruned off and the secondary buds will have an opportunity to grow. This is the safest route but clearly takes the longest.
Pruning is essential and should not be taken lightly. It gets crop management in motion and gives you a wonderful opportunity to spend time with the plants in the winter months, when it may seem more enjoyable to just look at them from the window of a warm house.