Balanced Pruning 3: Pre-Pruning
"Timely Viticulture-Balanced Pruning 2: Timing" dealt with the timing of pruning relative to dormancy, deacclimation, and bud break. The best thing to do is to try to delay pruning as long as practically possible. If you could accomplish all of your pruning in the last two weeks of March that would probably be best, although that is typically not enough time due to the size and labor limitations of most commercial vineyards.
If the vineyard is cordon/spur prune, one technique you can utilize to save you time and money is to “pre-prune,” “double prune,” or “rough prune” before you “finish” pruning down to your 2-3 bud spurs.
- This is ONLY for cordon and spur-trained/pruned vines.
- Pre-pruning of CANE pruned vines will eliminate critical portions of renewal fruiting canes.
- Pre-pruning of CANE pruned vines will eliminate critical portions of renewal fruiting canes.
- Pre-pruning can save time and money as this operation can be accomplished by “unskilled labor” with some instruction and minimal supervision.
- It can be accomplished at any time – much before you need to do the “final” pruning.
- It can also be accomplished with simple hand tools or “mechanized.”
- Utilize manual or powered loppers or hand pruning shears
- Hand-held or mounted hedge trimmers or shear type equipment
Note – always be careful when using mechanical equipment in close proximity to trellis wires!
- Specifically designed tractor-mounted pre-pruning attachments
Procedures
- Make cuts just above the first catch wire.
- Leave approximately 12 inch long spurs/canes.
- Pull all the wood (old canes) from the upper canopy from between the upper catch wires.
- Dispose of properly to reduce disease inoculum.
- The “trained pruner” can then go through and make the final cuts at the appropriate time
- Final timing based on variety and relative bud break timing
Double pruning vines are desirable for varieties that are susceptible to winter injury and/or prone to early frost damage.
- “Rough pruning” will inhibit the development of the critical count buds on the spurs (apical dominance) that will ultimately be maintained compared to cutting directly back to a 2-3 bud spur.
- For early budding varieties (Chardonnay) pruning to the final 2-3 bud spur is accomplished only after the danger of late frosts has passed.
- To extend this delay of budding, the 12-inch spur can first be trimmed to 6 inches following bud break, then trimmed down to the final 2-3 bud spur after all risk of frost has passed.
As much as possible, prioritize your pruning schedule according to the relative susceptibility to winter injury of each variety.
- Prune vines on the best sites first and the worst sites last.
- Prune American varieties first
- Followed by the cold-resistant hybrids (Foch, Baco Noir, Seyval)
- Followed by the more cold-sensitive hybrids (Vidal, Traminette Chambourcin)
- Save the vinifera for last, doing the least cold-sensitive first. (Riesling, Cabernet Franc)
- And the more sensitive vinifera (Merlot?) for very last.
- You may have developed a feel for the “relative” cold sensitivity of the vinifera varieties at your site based on experiences in test winters. Remember, the relative hardiness may change from region to region and vineyard to vineyard.
- Also, early budding varieties (Chardonnay) should be pruned as late a possible to delay bud break and avoid late frosts. Rough prune first as described above, and only make final cuts down to count buds after all danger of frost has passed.