Selection and Propagation of Bog Blueberry Plants for Alaskan Food Security
Bog blueberry, Vaccinium uliginosum, grows across millions of acres of the circumpolar north. It has been a staple food for indigenous people throughout history. Domestic blueberries (V. corymbosum, V. angustifolium, and hybrids) do not survive the winters in interior Alaska. Most Alaskans prefer the flavor of the wild bog blueberries to commercial blueberries, and recent scientific studies have identified high concentrations of antioxidants and pharmaceuticals in the wild berries. No varieties of the bog blueberry have ever been developed for domestic production. The wild bushes do not spread by underground rhizomes like most domestic blueberries, but propagate mainly by seed and layering.
Several years ago, we recognized tremendous variability among the growth and production of the bog blueberry plants. We started harvesting berries and germinating the seeds from plants that had phenological characteristics that appeared desirable for domestication, such as: large berries, clusters of berries, tall plants, good flavor, etc. The main problem was that seedlings are very fragile and easily killed. Also, it takes approximately six years before seedlings produce their first berries, and the desirable characteristics of the parent plant may not show up in the seedlings. A few years ago, Dr. Patricia Holloway at the University of Alaska Fairbanks perfected a method of propagating bog blueberries by rooting plant cuttings under a misting system. Propagation by cuttings offers several advantages to propagation by seeds in that the plantlets are genetically identical to the parent plant, and they start producing berries a year or two sooner than seedlings.
In this study, we proposed to collect cuttings from superior bog blueberry plants, plant half of the rooted cuttings on each of two farms, start evaluating the plants for possible domestication under uniform field conditions, and share the information with the public about how to select and propagate bog blueberries.
Obj. 1. Select 50 superior bog blueberry plants from diverse locations in Interior Alaska, collect 30 cuttings from each plant, and record the site characteristics and plant characteristics that make each plant desirable for propagation.
Obj. 2. Root and care for the cuttings; i.e. root 1,500 cuttings in a misting chamber, plant 1,000 of the best rooted cuttings (20 from each mother plant) in 3 1/2 inch pots, allow them to become dormant, overwinter them, start the plants off in a greenhouse the next spring, and move them outside in mid summer to harden them off.
Obj. 3. Plant 10 plants from each mother plant (500 for each farm) in rows in agricultural fields where they can be evaluated for desirable characteristics for domestication and mechanical harvesting.
Obj. 4. Share information about bog blueberries, their selection, propagation, and management with other berry growers by: a) giving a presentation to the Alaska Pioneer Fruit Growers Association in Anchorage; b) giving a presentation at the SARE Conference in Fairbanks; and c) holding an informal field day in cooperation with the Cooperative Extension Service at Papa’s Greenhouse.
In 2011, prior to this study, we had rooted approximately 200 bog blueberry plants using a misting system at the University of Alaska Fairbanks under the supervision of Dr. Patricia Holloway. That fall, we potted up about 100 of those plants and left the remaining 100 in the propagation trays and set all of the cuttings outside to overwinter under the snow. We potted up the remaining plants from the propagation trays in the spring of 2013. Those that were transplanted in the spring appeared to suffer less transplant shock than those that we had potted up the previous fall.
In June 2013, we purchased the parts and built a misting system for plant propagation in Papa’s Greenhouse at North Pole, Alaska. Victor Johansen, a local berry grower, observed our work and built a similar one in his greenhouse.
In June and July 2013, we identified 50 superior parent plants from within a 200-mile radius of Fairbanks and collected 30 cuttings from each for propagation. We dipped the cuttings in rooting compound, put them in the misting chamber, and set the timer to mist the cuttings for approximately 10 seconds every 15 minutes (Objective 1). In mid July, we realized that the heating mat under the propagation trays was no longer functioning, and we had to order another one, which did not arrive until mid-August. We also noticed that our water quality was not as good as that at the university, and we experienced quite a lot of variability in droplet size and spray distribution within the misting chamber.
In September, the plants went dormant, and it was apparent that some had rooted very well, but others had not. We put the propagation trays outside and left them under the snow until spring. In May, we separated the rooted cuttings from those that had not rooted and found that only 320 of our original 1,500 cuttings had sufficient roots to pot up. We put those in the greenhouse (Objective 2).
We intended to collect another 1,500 cuttings in July 2014 so we could complete our diversified collection of blueberry plants. We had two new mats for bottom heat, a supply of misting nozzles to exchange if they became partially clogged, and much more experience about rooting cuttings. However, in June we noticed that most of our small rooted cuttings were turning red and losing their leaves. We knew that blueberries require acidic soils for growth and had potted them up in an acid potting mix consisting of sphagnum moss, a small amount of compost, and a small amount of soil from under native blueberry plants to inoculate the cuttings with the native mycorrhiza. Apparently our water had too much lime and was overpowering the acidic soil. We purchased sulfuric acid to acidify the water and a good pH meter to monitor the acidity, but it was too late to save most of the cuttings that we had rooted in 2013.
Papa had conducted a separate study on blueberries during the fall of 2013. He has a row of blueberry plants in his garden that he had transplanted from the wild about four years ago. In the fall of 2013, he dug up two of his best plants and brought them into the greenhouse and bare rooted them. Then he went around the edges of each plant and divided the roots, collecting 20 plantlets with a few roots attached from each parent and potted them up in the same potting mix that we were using for the rooted cuttings. After making the root divisions, he returned what remained of the parent plants to his garden where they appeared shocked, but they were recovering the following summer. In the summer of 2014, while our newly rooted cuttings were dying in the greenhouse, his plants propagated by root division were thriving outside in the same potting soil and using the same irrigation water supplemented with occasional rains. (Is it possible that the roots from the established plants had mycorrhizal associations already established that allowed the new plants to extract nutrients from the soil whereas the newly rooted cuttings couldn’t?). Some of the plants propagated by root division were not only hardier than those propagated by cuttings, but some of them produced a few berries the first summer following root division. This method of propagation appears to be better for our water quality and less than pristine laboratory facilities.
During the summer of 2014, I dug up about 30 superior blueberry plants within 100 miles of Fairbanks and brought them home and divided the roots into 10 to 80 plants per parent plant and potted them up in 1-gallon pots using acidic peat from local peat bogs. This winter, I have 504 plants under the snow awaiting spring to see if they survive. Next summer, I plan to use those plants and the surviving rooted cuttings to establish observation rows on our two farms (Objective 3). Objective 4 was to disseminate the information to the public, as described under Impacts and Contributions.
Impacts and Contributions/Outcomes
On July 15, 2013, Victor Johansen, local berry grower, visited Papa’s Greenhouse and took notes on our mist propagation system and went home and duplicated the system.
On August 29, 2013, I was lunchtime speaker for the Greater Fairbanks Chamber of Commerce for a 30-minute talk about my SARE project for blueberry propagation (attendance 85).
On September 28, 2013, I gave a SARE project update and progress report to a Cooperative Extension Meeting of the Interior Alaska Small Fruit and Berry Growers (attendance 16).
On December 11, 2013, I was invited speaker at the Interior Alaska Chapter of the Alaska Native Plant Society regarding my SARE project for native blueberry propagation (attendance 14)
On January 9, 2014, I gave a SARE project update and progress report at a Cooperative Extension meeting of the Interior Alaska Small Fruit and Berry Growers (attendance 11).
On March 13, 2014, I was a speaker at the SARE conference in Fairbanks and gave an update on our bog blueberry propagation project and lead a discussion group on small fruits and berries (164 present).
On April 5, 2014, I was a speaker at the Annual Meeting of the Fairbanks Farm Bureau at Chena Hot Springs. I discussed the SARE project and gave on overview of wild blueberry selection and propagation (36 present).
On June 19, 2014, I met Steve Seefeldt and Darcy Etcheverry from Cooperative Extension Service at Papa’s Greenhouse and showed them the misting chamber and discussed the blueberry propagation work that we had done.
July 13, 2014, I took Wayne and Renee Miller, local blueberry enthusiasts, berry picking north of Fairbanks and showed them how I selected superior blueberry plants.
July 14, 2014, I made two trips to Papa’s greenhouse taking SARE representatives, Dr. Robert Newhall (in the morning) and Dr. Teryl Roper and wife (in the afternoon) to discuss progress and challenges with the blueberry project.
July 19, 2014, I took Barbara Ebbesson, local berry enthusiast, blueberry picking west of Fairbanks and showed her how I dug up plants and made root divisions.
August 13, 2014, six members of the Alaska Pioneer Fruit Growers Association from Anchorage called me to say that they were in Fairbanks. I took them to Papa’s to see our blueberry project, then we went out and dug up some native plants and I showed them how to divide them. They took two bags of plants back to Anchorage with plans to collect others on the way home.
Throughout the summer, numerous neighbors stopped at Papa’s Greenhouse and observed the blueberry project. He did not keep records of all the visitors or their interests.
I am now preparing an information paper on what works and what does not in propagating Alaskan blueberries. Most people in Alaska believe that bog blueberries can’t be successfully transplanted or propagated. However, I have found that I can propagate them by layering, from seed, from cuttings, and from root divisions. Some methods of propagation produce plantlets that are very delicate, and some propagated plants take years to produce berries. Plus, they need to be in acidic soil and properly cared for during that time. With the rapid population turnover in Alaska, most people probably will nothave the patience to establish plantings of bog blueberries. However, once we figure out how to mechanically harvest these berries, I think commercial farms of bog blueberries will be viable operations in interior Alaska.
Professor of Horticulture
Univ. of Alaska Fairbanks
172 Arctic Health Research Bldg.
P.O. Box 757140
Fairbanks, AK 99775-7140
Office Phone: 9074746686