Just noticed that I hadn't updated the blog on what happened with the Edmonton grapes in 2011. The year wasn't very warm and we had the usual 800 degree days of heat over the summer but with some of the vines located near the house they get extra reflected sun and radiated heat. Hard to measure how much but they ripened very well this year. The key was that they also had about 150 frost free days of growing and we picked them on October 10th, 2011. This is about an extra 2 weeks more than usual.
The St.Croix had some winter kill from the hard frost of September 15th, 2010. So even before winter had arrived the vines had been damaged. On this day in September we recorded -6c and the vines were barely starting to harden off, the fruit was only at 13-14 brix on the best clusters, so this really affected the vines going into winter. In fact, it probably had already killed some of the canes and at least part of the trunk on one vines. Come spring 2011, one of the 5 vines died off completely, yet we had alot of snow cover and did not have a very cold winter so the kill was largely a function of the extremely cold and early frost in September 2010. Come spring we had about 50% bud survival on the 4 vines that made it and many were secondary buds that made it. Consequently fruit production was low on the St. Croix.
The Acadie Blanc is not supposed to be a hardy as St. Croix but it had no winter damage and excellent bud survival, probably in the neighborhood of 85-90%. This vine is right up beside the house so first off it did not get exposed to the same cold harshness of the September 2010 frost that the St. Croix did. While it did get frosted enough to loose its leaves it was probably only -3 to -4 near to the house rather than -6 out in the yard, and the vine was already more advanced in terms of hardening off. So it was in better shape to withstand the frost and better shape going into winter.
The St. Croix did well and achieved brix of 17-18 with ph of about 3.1. The Acadie Blanc did even better achieving brix of 19-20 with similar ph of 3.1. Not many clusters on the Acadie as it is only a few years old but in 2012 we hope to have more. Both these grape varieties could have been picked earlier had they been threatened with frost, however, they both ripened well. Overall these are excellent numbers for grapes that most would say should not grow well in Edmonton with winter lows of -35c to -37c, average of 135-140 frost free days and summers with 800 degree days growing of heat. If the canes and vines are layed down on the ground in winter and they have some good snow cover, these vines can produce grapes that can be used for wine or eating in the Edmonton climate.