Haskap Variety Evaluation
Haskap, an edible honeysuckle (Lonicera caerulea var. edulis), is an exciting new fruit option for growers in western Montana. Also known as honeyberries, yezberries, and blue honeysuckle, haskaps can be used just like blueberries. Unlike blueberries, they grow well in many soil types. Haskaps are extremely cold-hardy (zone 2) and produce relatively early in the season (late June-July), which has the potential to fill a market gap in fresh fruit. However, haskap plants take 3-4 seasons to produce profitable yields. Additionally, an investment in wildlife protection once fruit has set is imperative to success. This research project aims to determine varieties that will thrive, are palatable, and are easily harvestable in western Montana.
Montana State University has been evaluating 16 haskap varieties for yields, flavor, aesthetic qualities, and cold-hardiness. Eight varieties were planted at four sites across the state (Corvallis-WARC, Bozeman-MSU, Kalispell-FVCC, and Helena) in 2015. At the Western Agricultural Research Center (WARC), eight additional varieties were planted. Each variety was represented at each site by 9 plants (3 plants/block x 3 blocks).
Among the earliest blooming varieties, 'Indigo Gem' exhibited the highest yields, largest average berry size, excellent palatability, and was easily harvestable with a mechanical shaker. All other early-blooming varieties yielded poorly (<1 lb/plant), and were less palatable than 'Indigo Gem'.
Cold damage was observed at the WARC site in 'Blue Goose', 'Sugar Mountain Blue', and 'Wild Treasure'. These varieties broke bud in February after a warm spell in 2018. Once temperatures dropped again, new growth on these varieties died back. Conditions were cooler at the FVCC site, so 'Sugar Mountain Blue' was more productive (2.1 lbs/plant) than at the WARC site. 'Blue Corn' exhibited a tonic-like aftertaste and performed poorly overall; therefore, it was removed from trials in spring of 2018.
'Aurora' and 'Borealis'—the two mid-maturity varieties—were productive, had excellent flavor (preferable over all varieties), and were very easy to harvest with a mechanical shaker. Additionally, these varieties tend to ripen evenly, resulting in minimal fruit loss prior to harvest.
The Oregon State University varieties developed by Maxine Thomson mature later and all produced high yields (7-13 lbs/bush over three years) with good flavor. Some varieties dropped fruit prior to achieving full ripeness ('Taka', 'Kawai', '41-75', and '85-19'). Others held tight to the fruit ('Tana', and 'Keiko') and required more effort to harvest. 'Tana' and '85-19' have been the most productive. 'Taka', 'Keiko', and '79-91' have larger berries that are similar in size to University of Saskatchewan varieties. 'Solo', '79-91', and '85-19' have relatively sweeter berries that are similar in sugar content to University of Saskatchewan varieties.
Table 1. Haskap results from the WARC-Corvallis site.
|Variety||Harvest Time*||Source||Yields (lbs/plant)||Berry Weight (g)||Sugar (⁰Bx)|
|'Blue Goose'||Early||Berries Unlimited||0||0.1||0.2||0.3||0.6||14.4|
|'Sugar Mountain Blue'||Early||Russia||0||0.5||0.3||0.8||1.0||16.7|
|'Blue Corn'||Early||Berries Unlimited||0||0.9||NA||0.9||0.8||14.6|
|'Wild Treasure'||Early||Berries Unlimited||0||0.4||0.5||0.9||0.8||16.3|
|'Aurora'||Mid||U. of Saskatchewan||<0.1||1.2||3.7||4.9||1.7||16.0|
|'Indigo Gem'||Early||U. of Saskatchewan||0||1.2||4.9||6.1||1.1||17.7|
|'Borealis'||Mid||U. of Saskatchewan||<0.1||1.8||4.9||6.7||1.5||16.2|
|'79-91'||Late||Oregon State Univ||0.1||3.2||3.7||7.0||1.5||17.0|
|'Solo'||Late||Oregon State Univ||0.2||2.0||5.1||7.3||1.3||16.3|
|'41-75'||Late||Oregon State Univ||0.4||3.3||3.6||7.3||1.3||13.0|
|'Keiko'||Late||Oregon State Univ||0.3||2.9||4.6||7.8||1.3||15.5|
|'Taka'||Late||Oregon State Univ||0.1||3.3||4.5||7.9||1.5||13.9|
|'Kawai'||Late||Oregon State Univ||0.2||3.9||4.0||8.1||1.5||13.6|
|'Tana'||Late||Oregon State Univ||0.2||3.9||7.0||11.1||1.4||14.7|
|'85-19'||Late||Oregon State Univ||0.2||4.4||8.7||13.3||1.3||
Note: OSU plants were larger at planting in 2015 (2 years older) and are still larger than other varieties. This is, in part, why they had higher yields. Numbered varieties are not yet commercially available. We are also evaluating 'Boreal Blizzard', and 'Boreal Beauty', but they are not yet mature enough to compare. 'Honeybee', 'Strawberry Sensation', and 'Blue Moose' are planted outside of the trials.
*early harvest=third week of June, mid harvest=last week of June-early July, late harvest=first two weeks in July.
Table 2. Haskap results from the FVCC-Kalispell site.
|Variety||Harvest Time*||Source||Yield (lbs/plant)||Berry Weight (g)||Sugar (⁰Bx)|
|'Sugar Mountain Blue'||Early||Russia||2.1||0.9||16.6|
|'Aurora'||Mid||U. of Saskatchewan||3.9||2.0||15.6|
|'Indigo Gem'||Early||U. of Saskatchewan||4.9||1.3||17.7|
|'Borealis'||Mid||U. of Saskatchewan||3.7||1.7||14.4|
|'Solo'||Late||Oregon State Univ||4.1||1.5||15.4|
|'41-75'||Late||Oregon State Univ||3.9||1.4||13.8|
|'85-19'||Late||Oregon State Univ||6.7||1.6||15.0|
Many of the early-blooming haskap varieties exhibited low productivity (<1 lb/bush over 4 years), averaged relatively small berries (<1 g/berry), tasted unappealing, and were prone to winter injury when warm spells broke dormancy. 'Indigo Gem' performed relatively well for the early variety group. However, it should be noted that 'Sugar Mountain Blue' was more productive in the Kalispell trials than in Corvallis. 'Aurora' and 'Borealis' produced large berries, were easy to harvest, and demonstrated excellent flavor. Many of the varieties sourced from Oregon State University showed strong yields and good flavor. However, these varieties may be best suited for small scale plantings due to their tendency to be difficult to harvest.