Is it colder above or below the snow? A quick mid-winter update

We were out on the terraces today checking on the the soil temperatures at 8 inches (20 cm) and 16 inches (40 cm) depth. While the air temperature was in the mid 20s Fahrenheit (-3 C), there is concern that another long cold spell could push the soil temperature below what is tolerated by some of our grapevine varieties. Even after piling more snow on the terrace around the soil temperature probes, there hasn't been much of a rise in temperature.

Stay tuned for more winter updates!

The 2022 Season - moving grapevines

 

Another year in the books, as they say. We were very focused this season on relocating the vineyard. After discovering that terraces greatly increase the soil temperature on hillsides here in Interior Alaska, we began planning how to move our 150 or so grapevines from their field location to a series of terraces we had built a number of years ago. Those terraces had been planted with currants, gooseberries, and peonies within the last decade. Since that time, the terraces have begun to slump and we kind of ignored them other than in the fall during currant and gooseberry harvest. The peonies did not like that location from the very beginning. While the soil was much warmer, it was also rockier – and that tended to damage the delicate flower buds peonies are known for. So, why not repurpose the terraces!

 

Starting as soon as the snow melted, we began pulling hundreds of willow, alder, birch, and poplar saplings from the terraces. We targeted the top two terraces for planting this year. We hope to double that number next year, but there are so many saplings that it is slow going. By late summer, we had augered the post holes for the trellises on both terraces and had begun planting vines. We were able to fit 20 vines on each terrace, spaced 6 ft (2 m) apart in the row. The terraces are 7 ft (2.2 m) wide and about 30 inches (0.75 m) tall at the nose. With these dimensions, the terraces intercept quite a bit of sunlight during the early summer, with soil temperatures reaching 75-85 degrees Fahrenheit (25-30 C) by early July at a depth of 8 inches (20 cm). That may not sound unusual, but here in the cold north, the normal temperature at that depth mid-summer is about 50 Fahrenheit (10 C). In fact, as part of our ongoing experiment with grapevines on the terraces, we dug holes for every potted vine and left them in the holes for almost the entire summer. The difference in root growth and plant vigor between the terraces and the field was quite obvious.

 

By the end of September, we had installed the posts and the vines were hardening off quite nicely for winter (see picture above). Our first freeze came on October 9^th, about 2 weeks later than expected. What we discovered next was a bit surprising. We had installed two thermometers on the second terrace the previous summer and noticed over last winter, the temperature at 8 inches (20 cm) never dropped much below 30 F (-1C). However, this year fall was on the dry side, with little snow falling until mid-November. That combined with air temps below freezing for extended periods of time quickly removed any remaining summer heat and the soil temperature at 8 inches (20 cm) dropped to 17F (-8 C) by the end of November. Grapevine roots of some species are rather sensitive to cold, with Vitis vinifera suffering substantial injury or death below about 23F (-5 C). Other vines we have, including pure V. riparia and V. amurensis, have much hardier roots and should not be injured at this temperature. This finding does suggest a limit to the use of terraces on the farm for growing cold tender plants. And we are not out of the woods yet. As of today, the terraces have again dropped below 20 F (-7 C) due to a recent cold spell. We will find out next spring which vines are more susceptible to root damage!

 

Speaking of peonies, we continue to move them from the terraces and other raised beds we have to a larger field location. Currently, we have about 700 planted out in the field with varying degrees of success. To augment the peonies, we upped our production of other flowers this year, selling to a local florist throughout the summer months. Next year we plan to double or triple our flower production as we open up more areas to plant them. The major issue with expansion continues to be the lack of water. Our 2000 gallons (7560 l) of water we capture from melting snow in the spring goes quickly, and it is usually early August before the summer rains arrive. We will likely be hauling water in to supplement.

 

Next year may also be the last year we hold our annual plant sale. This will be our 15^th May plant sale and if the recent trend of decreasing sales holds, it will not be economically feasible going forward. We started the plant sale in 2009 as an early season source of income for the farm, but the timing has always interfered with the completion of other important chores. Moreover, with the increase in flower production, we will need more indoor space for flower seedlings – and there isn’t much space to begin with. So, something has to go. Shifting away from growing seedlings for the plant sale will allow us to focus on flower sales and our ultimate goal of making wine from the vineyard. Somewhere in between, we need to drill a well!

 

The short-term forecast is for a pretty chilly January and early February, but a nice warm up in March and April. Then it will be time to check in on the vineyard terraces to see which vines survived and which ones will need to be replaced. Stay tuned!

Spring 2022 Farm Tour

Spring is about to wipe out our 30-inch snowpack, so we thought we'd take a tour from above the snow. We have high hopes for a number of trials/experiments we are/have been running, including playing with some wild Vitis riparia cuttings from northeastern Montana and North Dakota that show some promise in overwintering new growth - exciting! Enjoy.

The 2021 growing season and … the new location for the vineyard!

 The 2020-2021 winter wasn’t particularly harsh (-27F/-33C) and the snow held off until mid-spring for the most part. Going into the spring thaw, there was about 43 inches (109 cm) of snow on the ground. We melted enough snow to create 2000 gallons (7500 l) of water for crops. Summer was dry right up until the second week in August, when we received 7 inches (178 mm) of rain over a two-week period. Fall was pretty routine, with the first hard freeze coming on September 20. That yielded a frost-free season of 115 days, but a grape-growing season of 143 days (bracketed by 28F/-2C on either end). The farm accumulated 1139 GDD 50F (633 GDD 10C), with a maximum temperature of 88F (31C) on August 3^rd.

 

2021 marked our 13^th annual spring plant sale. We saw a lot of interest in gardening as a primary source of vegetables for families. It is good to see people returning to home gardening.

 

We went a little deeper into flower production this past summer. We delivered bouquets to a local BnB during the summer. That encouraged us to expand our flower production and to plan for offering a bouquet subscription to local residents in 2022. We plan to offer a 10-week subscription and the option to break that 10 weeks into two 5-week subscription options.

 

Unfortunately, our blackberry patch was afflicted by disease following a very wet August and September 2020. None of the canes (even on Stenulson) survived the winter. It was odd not to see an abundance of blackberry flowers on Stenulson. We continue to work with Stenulson to see if we can get it to set fruit. We believe that the original plants we received were not self-fruitful. Thus, the flowers appear and bees visit them, but they have never produced actual berries. As Stenulson is a selection from the wild, it is likely dioecious and our plants need a pollinator. It continues to spread (slowly) from its original planting and seems to tolerate temperatures down to -35F (-37C), so we continue to work with it in hopes of developing a reliable source of blackberries.

 

We continue to study the needs of our grapevines. After digging the majority of vines in the vineyard up and checking on them two years ago, we realized that something was seriously wrong. There was little, if any, new root growth on most of the vines. Our soil temperature profile records indicate that while the ground does not get particularly cold over the winter (staying mostly above 20F/-7C), it does not get very warm in the summer (peaking around 50F-55F/10C-12C). Studies with V. vinifera suggest that grapevines prefer soil temperatures of 60F and above (15C+). We examined the soil around Arthur (Pinchbeck) to see why it is able to grow with much more vigor than the other vines. We realized that several years before planting Arthur, a couple of buckets of small rocks were dumped in a pile about a foot (25cm) away from where Arthur was planted. We added soil thermometers under the pile of rocks and found that the soil was 10F (6C) warmer under the pile of rocks. A quick watering experiment this past summer showed us that Arthur’s roots were confined mainly to the area under the rock pile. We began piling rocks around a few other vines, but saw little difference before the growing season came to an end. With any luck they were putting down new roots in the warmer soil. This whole discovery (spurred on by a discussion with an international group of grape breeders) encouraged us to look around the farm for other areas where the soil was warmer. Hauling around buckets of rocks is rather difficult and time consuming, after all. We ended up digging a hole in one of our terraces (which we’d all but abandoned, since they tend to erode and slump). Eureka! We found it! Soil temperatures in the center of a terrace ranged from 60F (15C) to 75F (24C) in the top 16 inches (40 cm). Needless to say, we will be moving all 135 vines currently in the field/vineyard to our new terraced vineyard next summer.

 

We have identified another grape variety that has potential in Interior Alaska – Skujins 675. It is one of only a couple of vines that begins maturing its wood by early August and hardens off a few nodes (even with the cold ground in the field) before the first freeze. More to come on that variety. In addition, we acquired several wild selections of V. riparia from far eastern Montana and southern Manitoba this past year. One of those (SD 62-8-160 or “160” for short) defoiiated entirely on its own and seemed to harden off much of its growth before our first freeze on September 20. This is the only vine we have that does not require leaf removal to encourage wood formation in the fall. What a discovery! We have more wild selections from Montana and North Dakota sitting in our fridge and are anxious to see how they compare to 160.

 

This past year was also a victory in terms of rooting grape cuttings. In the past, we have followed the more conventional practice of using a combination of heat and moisture to trigger callus and root formation on cuttings. Our success rate has been fairly low and quite inconsistent. The method we “perfected” in 2021 relies on a mix of water and hydrogen peroxide to trigger root formation. It does not require any additional heat, but does require a sunny window. We had a 95% success rate at rooting dormant cuttings and found that the method also works on green cuttings, as well as on cuttings taken of a section of woody cane that contains a green shoot. Placing the woody end in the water/peroxide mix causes the woody portion to root quickly. There are a few caveats, but overall the process seems to be highly reliable. It has been tested by others on Chambourcin, a French hybrid, with great success. Others are testing the method on hard-to-root species, as well.

In a year marked by drought, excessive rain, disease, insect pests, rodent damage (yes, we lost a cherry tree to vole damage), and illness, there is still plenty to be thankful for and lots of new hypotheses to test. While moving the vineyard yet again will be a challenge (and that is after we remove the 100s of birch and willow saplings now established on the terraces), we believe it marks a turning point in our quest for a real, productive vineyard – even if “productive” doesn’t necessarily mean ripe grapes. We continue to pursue a grape crop, nonetheless, and vow to make the first wine from grapes grown outdoors at 65 degrees north.

Fall 2020 Farm Tour

 Here is our recent farm tour we recorded on October 17th. Enjoy!

It's 80 degrees . . . and the grapevines still aren't growing!

Last summer was a warm one, with numerous days topping 80F (27C). It was also on the dry side. The farm received 2.88 inches of rain (73 mm) during the three month period May through July. In the past, we assumed grapevines didn't grow much during the summer here because it was too cold - both the air and ground temps. Well, this year when we saw a string of very warm days and warm nights, we were puzzled to see the grapevines not growing more than they had in past summers (rainy or not). So, we contacted a very knowledgeable grape grower in Wisconsin. He asked how wet the ground was. WHAT? I thought grapevines didn't need water in places where it rains in the summer. Wrong!!! Research revealed that each vine requires 6-10 gallons of water each week, or an inch of rain. Well, we never get that much rain before August - and then the vines are starting to shut down. So, we started pouring water on a few vines to see what would happen. Our Arthur Pinchbeck (Canadian variety) vine literally took off! In 5 weeks it grew 5 ft - compared to 1.5 ft (0.5 m) last summer. Who says grapevines won't grow in Interior Alaska? At the end of the season, it was taller than me. It still remains to be seen how much of the vine hardened off sufficiently for the winter, but we're hoping for at least 3 ft. (1 m).

  All that being said, we were not able to duplicate the results on other vines for the most part. There were several reasons for this. First, was a lack of water. We hauled in water at the rate of 1000 gallons (3800 l) per week, but with a few acres of plants to water that didn't go very far. We sacrificed some currant plants (well, not entirely as they are still alive) to pour some water on a few other grapevines. Second, we're on a hillside (as you can see from the picture). Without proper equipment, it was difficult to get the water to soak in before it just ran off. Adding to the problem was that the ground was extremely dry from a lack of rain when we began watering the vines in earnest. Even Arthur Pinchbeck took 10 days to respond to the extra water, conceivably due to the absorption of the water by the surrounding dirt. When the rains came in August - 6 inches (150 cm) in the first two weeks - the growing season was already beginning to wind down. We stopped watering the vines in late July and a natural drought (which grapevines need to adequately prepare for the winter) began the third week in August.
  We added a number of new cultivars to our trials this past summer, including ES M-1-27 (a very early variety bred by the late Elmer Swenson). Vandal Cliche, and Marquette. We also were able to add Baltica back into our collection after losing it two years ago before we could get it planted in the vineyard.
 We also reorganized the existing vineyard (now at about 135 plants on 1/8 acre or 0.05 ha). When we did this a few new lessons were learned. Every vine that we dug up, with the exception of Sipaska and Louise Swenson, had really no new root development since being planted between 1 and 3 years ago. None, nada, zilch. That was disappointing. And, in cases where the crown of the vine was planted 12 inches (30 cm) deep (most were planted only 3-5 inches (<15 cm) deep), all older roots above about 8 inches (20 cm) were dead. There were a few white new ones in that zone, but no older roots. Why? Good question. Perhaps a lack of water. Perhaps winter cold (though we have documented that the ground doesn't drop much below freezing in this zone, which should not be a problem for our hardier vines). In the case of Sipaska and Louise Swenson, they both had older roots extending 12 inches (30 cm) or more down into the ground. Nice, healthy looking roots at that. And Louise Swenson is supposed to be particularly prone to drought stress! Now that the vineyard is reorganized with all vines planted at least 8 inches (20 cm) deep, we hope for better growth in the future. The obvious lack of a root mass on each vine also contributed to the poor summer growth on vines.
  One thing that reorganization did not solve, was the way we were planning on trellising the vines. Reading the literature, it is suggested that vines be planted in rows that run north-south and up and down the hillside (where appropriate). Well, since our land slopes downhill to the south, we were planning on trellising them up/down the slope. That would improve the stability of the trellis, too, since all stress would be pulling parallel to the row alignment and we could counterbalance that with a ground auger on the uphill side of the trellis. However, we realized that orienting the trellis this way meant that the fruiting zones in each row (based on a low-cordon training system with vertical shoot positioning or VSP) would be shaded until almost 11 am and again after about 5 pm each day. Remember that at 65 degrees north latitude, the sun doesn't rise all that far above the horizon for much of the summer. Our original layout was based on rows running east-west (across the slope rather than down it). Putting a trellis up for that system would mean that the freeze-thaw cycles in the ground would allow the trellises to slowly lean over downhill (that is what the pilings are doing under the cabin at the moment). An east-west alignment would greatly reduce shading, but would not allow full sun exposure of the north-facing side of the clusters. Turns out that this problem would not be solved using north-south rows, unless we spaced the rows out significantly more than our current 6 ft (2 m) row spacing. The jury is still out on the best orientation. We will probably run a trial using both orientations for the same variety (probably Alpenglow, since that is a readily available variety that hardens off significant wood for the winter) and see what happens.
  Another discovery this past summer was the importance of leaf pulling in the far north for more than fruit exposure. Typically, "northern" vineyards (but still well south of our vineyard) practice pulling leaves in the fruiting zone once veraison has begun to get more sunlight on the fruit and encourage the ripening process (adds heat and direct sunlight on the berries). Well, as our serendipitous experiments usually turn out, we learned a valuable lesson in "leaf pulling" due to the very dry summer and abundant sunshine. The bottom 3 ft (1 m) of our Arthur Pinchbeck vine had all leaves facing north. Odd, I know, but that is how it grew. Above that, the leaves oriented in all directions. Our theory (based on fairly sound science) was that the leaves were trying to avoid the sunlight to reduce water loss and oriented themselves as far "out of the sun" as possible. This is a common strategy used by plants that are water stressed. By turning the top of the leaf (most photosynthetically active surface) away from direct sunlight, photosynthesis is reduced. In addition the leaf temperature is reduced, stomatal opening is reduced, and water loss decreases. Uh, that's all well and good, but why was that important this year. Turns out that here, the hardening off of grapevine shoots in the fall (and subsequent survival and budding out in the spring) is very dependent on sunlight exposure during the latter half of the summer. From our observations, shoots need more than 4 weeks of direct sunlight on them in order to adequately mature the shoot and begin forming periderm. We saw periderm formation on Arthur Pinchbeck and Alpenglow by mid-July this year - compared to mid- to late- August in other years. Once we started pulling leaves on other varieties, we saw significantly more periderm formation on them than in past years. The most noticeable variety was ES 80. This Elmer Swenson variety (one of his first) has turned yellow and  dropped its leaves in the fall every year in the past. However, it has never formed periderm. This year, with its basal leaves pulled beginning in late July, it developed periderm over most of its shoot and looked really good going into the winter. It has fairly large leaves that tend to shade the shoot. Remove the leaves later in the season and viola! it forms periderm. Leaf pulling did not affect all vines equally and our largely V. labrusca derived vines were the least affected. Those with more V. riparian or V. amurensis responded more strongly.
  Speaking of V. amurensis, we also ran an experiment with grow tubes this summer and found that this species requires substantially more water than our other species/varieties. Even in the middle of the heat and dryness, there was moisture condensing inside the grow tube on Amur-1 (one of two remaining seedlings from several years ago). This species comes from northeasern China/Russia where the summers are hot and very humid and winters are cold and very dry. So, summer droughts are not its specialty - winter droughts, on the other hand, it handles with ease. We will have to really water that one well next summer to see if it will grow better. As usual, this vine was completely dormant 123 days after budswell (May 13-September 13). Now if it will produce fruit and ripen it in that time, we're onto something.
  Understand that when we say "serendipitous experiment", these experiments arose entirely on their own. We just observed the results. A well documented serendipitous experiment here on the farm was the discovery that covering trailing blackberries with row cover over the winter improved winter survival. We were too busy one winter to remove the row cover we were using to help ripen blackberries in the fall and the next spring we found live canes under the row cover and dead canes beyond the cover. We now (almost always) cover our most productive blackberry plants with row cover for the winter. More on that ongoing experiment in a future post.

Spring 2019 Farm Tour