Brrrr It's Cold Outside!

 

We are currently sitting at about -40F (-40C)! We have been in a cold snap for almost a week and have about that much longer to go before warmer weather returns. With a few feet of snow on the ground, some of our smaller bushes (and all of the terrace vineyard vines) are protected from the majority of this cold. However, we have a number of taller bushes and small trees that are taking the full brunt of the cold. While we have seen -41F at the farm in the last 10 years and know which of these bushes and trees should make it through the cold with little to no damage, there is always the question of how well prepared they were for winter. Those that suffered from too little water early in the summer or too much water late in the summer, may be more susceptible to winter injury in these temperatures. Other bushes that are not so hardy, such as black currants and our unnamed, seedling aronia bushes, will likely die back to the snow line. That still leaves plenty of wood below the snow to leaf out in the spring and rejuvenate the plant. There will be a good amount of pruning needed on these plants next summer. It is always a gamble with plants that aren’t completely hardy at our location, but -40F only comes about once every 10 years, so in the intervening years we can get quite a nice crop.

 

The vineyard is all nestled in, but there is still a risk from cold periods like our current one if the cold lasts too long. Snow is not a perfect insulator, so it slowly loses heat from the ground over time. The vines that are planted out on the terraces should be fine, but we have a large number of potted vines that are in pretty dry soil at this time. They are more susceptible to damage. We also have a couple of Vitis vinifera (European grapes) in pots that are not very cold tolerant (when compared to others that are hardy to -30F to -40F; -35C to -40C). These varieties include Gewürztraminer and Müller-Thurgau. The roots on these vines will probably suffer some significant damage and the vines may die outright from the cold. This is a big reason why we don’t focus on the grape varieties you would typically associate with wines. On the other hand, great strides have been made in recent years in breeding cold-hardy (still a relative term when growing them in Interior Alaska) grapes that also make quite acceptable wine. Something that a lot of people don’t realize, but can be very important when growing grapevines in the far north is that one of the factors in hardiness is the duration of cold temperatures. Even the hardiest vines will die back if the cold (maybe not even severe cold) lasts too long. This coming spring, we will find out if the vines we have planted on the terraces experienced too many hours below 0F (-18C). Fingers crossed!

 

The cold may also impact our cut-flower trials that we started last August. Two years ago, we planted delphinium (known to be fully hardy in Interior Alaska) and campanula (Canterbury Bells) in a raised bed and they both survived the 2022-2023 winter very well. However, it only dropped to -22F (-30C) in January. This past fall, we planted more campanula, along with several other flower varieties (sweet William, feverfew, rudbeckia, and yarrow. The yarrow will do well, as it is native to Interior Alaska, but the others probably won’t make it. Nevertheless, we won’t know until the snow melts and the beds start to thaw in April. Yet again, fingers crossed.

There are a few benefits to the cold! It usually reduces the bug population for a summer – never a bad thing. It also makes the tourists go home, at least for a few weeks. We then can walk through the stores in relative peace. And while that may sound a little selfish, anyone that lives in a major tourism area can attest that area residents can always use a little respite from the pressures of tourism to reinvigorate them for the upcoming tourist season.

The Summer of 2023 marked the first full growing season of grapevines planted on the terraces. We planted 40 different vines (each a different variety) in the fall of 2022 once we found that the terraces boosted soil temps from the 40s-50s F (5-12C) to the 60s-70s (15-25C) down as deep as 16 inches (40 cm). We hoped that our grapevines would actually develop mature root systems given this newfound warmth. However, 2023 provided mixed results. Baltica (pictured above) exploded in growth in late June and reached a total of 70 inches (178 cm) of new growth by mid-August. It seemed quite happy! Other vines produced a total of 24-30 inches (60-75 cm), and still others barely made it out of the ground. You might be wondering why the difference. Well, it probably didn’t help that we planted in the fall before the vines had dropped their leaves. So, some were quite shocked by the move. Quite a few of these vines also prefer warmer summers than we typically get, as well. We suspect there will always be “laggers” that are just not happy in cool weather. We will know more after this next summer, as more vines stretch their roots out and become better established.

Some standouts (besides Baltica) were Arthur Pinchbeck, Beichun, Pilgrim grape (V. xnovae-angliae), Manitoba V. riparia 64, Louise Swenson, Totmur, ES N-11-1/2, and Skujins-675.

We added a number of new varieties/selections last spring that included a variety of Vitis species. Named selections included Severnyi (Russian cross), Rondo, and Müller Thurgau (V. vinifera). We also replaced varieties that had died while in the field: John Viola, Swenson Red, LaCrosse, and St. Croix. Our request from the USDA germplasm in New York included V. riparia selections RA-66-7, RA-66-8, HP-1 (male partner of HP-2, which is already out on the terraces), SD 62-11-42, L505 (possibly a typo of L50S), and USSR 1502. We were looking for wild selections that were very hardy that would also shut down properly in the fall (an issue on the farm with our very long days). Our search for early senescing V. riparia was spurred on after whitnessing SD 62-8-160 going dormant early in the fall. This is a wild selection from far eastern Montana. Since then, we have found RA-66-5, a male V. riparia also from far eastern Montana, that begins shutting down in late July and has formed periderm over more than 50% of its new growth by the time our first frost occurs.

We played with a few vines that managed to flower after overwintering in pots sunk into holes on the terraces. Around July 4^th, two varieties bloomed and set some tiny berries. Manitoba V. riparia 37 (from Riding Mountain Provincial Park, Manitoba) and Elmer Swenson’s ES 9-7-48 were assisted in pollination by Beichun and RA-66-5, which also flowered around that time. While both R. 37 and ES 9-7-48 were flowering off of secondary buds (buds that did not form at the farm), we were curious as to whether either would get close to ripe before the first freeze around the end of September. And, while neither vine was very big and the resulting berries not representative of what mature vines would produce, our curiosity reigned. By the end of August, berries on both varieties were going through veraison, the time when red and blue grapes turn from green to their final color. That is where the story of V. riparia 37 ends. Apparently, it decided to take the rest of the fall off and never fully changed the color of its berries. Rats! ES 9-7-48, on the other hand, marched on in the face of cool September weather – well right up until the voles thought the berries were ripe enough to pick. On September 4^th, we measured the brix at 9. Far from ripe, but if the voles hadn’t found the other two berries, we suspect they would have been ripe enough to eat by the time of our first frost came on September 23^rd. This variety has some potential at the farm!

We also played with some berries on Rondo, which we had shipped in in late June. It was flowering when we received it, so these berries would not be representative of actual farm conditions. We watched the berries grow and turn color and waited for them to sweeten up. We waited ... and waited … and waited. Finally, we picked the last two berries on September 18^th with the threat of frost looming on the horizon. Only 13 and 15 brix, and if you ask me not much flavor. Well, we’ll try them again if they survive the winter and get planted out on the terraces. This variety is not really hardy in our winter conditions without protection, but it is worth a try if for nothing more than breeding.

We recorded a series of videos between August 17^th and October 16^th to document the formation of periderm on all of our vines. As periderm (bark) formation is critical to winter survival of grapes, this is a vital part of our studies. Most varieties struggle to know when it is time to shut down and prepare for the winter, because of our very long days and short growing season. This year, there were some notable standouts: Arthur Pinchbeck, Louise Swenson, ES 10-18-30, ES N-11-1/2, Skujins-675, Mandan, V. riparia RA-66-5, Petite Pearl, and Skujins-675. You will notice that Baltica did not make that list. From our past experience with Baltica and notes from trials in Scotland where very early fall frosts are a problem, Baltica often goes into the fall bright green, rather than the nice red-brown color grape growers want to see. For us this year, it started to form periderm just days before our first frost and suffered significant damage when the first 23F (-5C) night arrived. We will have to wait and see if anything survived the cold. It is possible that pulling bottom leaves to increase sun exposure starting at the end of July may hasten periderm development on that variety.

As for cut flower production, we had successful harvests of ranunculus, bupleurum, Rubenza cosmos (love this one!), snapdragons, feverfew, and sunflowers. Production spanned from late June through mid-September, when we pulled out the remaining crops to prepare for the winter. In 2022, we trialed fall planting of campanula (Canterbury Bells) and were amazed when 85% of the plants came back this past spring. We ran another trial this past fall with a few more flower varieties, hoping to reduce the pressure of spring planting. Most of them will probably not make it, but at least we know the campanula and yarrow will. They will fill early season bouquets with the delphinium growing beside them.

In terms of other fruits, we harvested about a dozen apples and apple-crabs (Clair 4, Parkland, Prairie Sun, and Shafer), handfuls of Regent serviceberries, and 1.5 pounds (0.7 kg) of aronia berries. Birds got to most everything else before we knew anything was ripe. This included red, white, and black currants, gooseberries, and blueberries.

Right now, we are deep into planning for the upcoming summer. Since we were not able (for health reasons) to plant any grapes out last summer, we are hoping to plant out another three terraces this next summer. We also hope to move dozens of serviceberries and apple trees to the food forest and make room for more grapes on the terraces. There may be a new blackberry variety joining our plot that is a potential pollinizer for Stenulson and we will be propagating Wild Treasure and working on enhancing its winter hardiness. We will be cleaning out two more raised beds to expand our cut flower production, as well. The year is starting off well and our fingers are crossed for another successful year on the farm and in the vineyard!