The winter of 2011-2012 was one of the warmest on record for the Edmonton area. We had a few days in the -30c to -35c range but not many. Overall the grape vines made it through the winter well. The five main varieties we have are doing well and even the Marechal Joffre had buds that survived the winter this year.
The St. Croix, and Acadie both had bud break around the 20th of May and have continued to show good growth. The St. Corix pictured below has been cropped back this year to guage how that affects ripening. We have limited the number of shoots to approximately 12 per meter and eliminated non producing and weak shoots. We are going to headge each shoot at the 10th leaf to encourage lateral growth, this would be in mid July. There is some research that suggests the laterals enhance maturity in the grapes at veraison and if done just prior to flowering, it enhances fruit set. However we are not pinching back any of the flower clusters this year, so the majority (approximately 80%) of shoots will have 2 clusters. See photo below;
The Acadie came through the winter really well. This vine continues to surprise me in this climate. It is supposed to be hardy to -30c but it seems to be hardier. There are some researchers who claim that vines will tend to climatize to a location and as such can endure colder tempertures than what was expected of them. However, on that note, we lay all our vines down in the winter to increase vines survival, so they are not really getting the full winters cold. The Acadie also is pruned to 12 shoots per meter but I've left a few shoots that are pushing at locations on the cordon where we there are holes. Each shoot has between 2 and 3 flower clusters. I'm going to pinch these back to maximum 2 clusters/shoot. See photo below;
This year the Marechal Joffre had a few surviving buds. In five years this has happened only one other year, so this is not a good grape vine for Edmonton. But what is interesting to see is that the all three buds (primary, secondary, and tertiary) from the same location have flower clusters. I'm going to leave all the shoots and all clusters on each shoot from this location to see how they mature.
The Other two varieties are the Baltica and Evangeline. These two vines are planted in very difficult soil which is mostly clay and they are having a diffiuclt time getting established. However, the Baltica has many buds and shoots this year and a few flower clusters this year. Three of the four Evangeline died back to the ground. Likely as these varieties get bigger and stronger at this location they will show greater survival rates.