Haskap Arrives in North America

From the Home Orchard Society


Dr. Maxine Thompson

Haskap berries are native to Hokkaido, the northern Island of Japan. Historically, wild-growing plants provided one of the few fruits available to the Aniu people, the indigenous population on this island. They appreciated their taste and also recognized their high nutritional value. In 1967, the Japanese began a program to domesticate this fruit. They collected and propagated outstanding plants form the wild, established regional trial plots to evaluate adaptability in different climates and to identify the very best selections. Plants were distributed to interested farmers who formed a growers cooperate to develop and market haskap processed products. Unfortunately, the original acreage and production of haskap has declined in recent years because hand-harvesting is cost-prohibitive. Farms are small and there is no berry harvesting machines in Hokkaido.

Haskap belongs to Lonicera caerulea L., a wide ranging species in northern regions of Eurasia and North America. The species, commonly called blue honeysuckle is divided into several subspecies base on distinct morphological traits and ecological adaptations. Russian scientists have developed many cultivars mainly from the Russian subsp. edulis and kamtschatica, which are well adapted to the severely cold regions of Russia, but not to more moderate climates. A few of these are currently being marketed in North America as “honeyberries”. Haskap belongs in the subspecies emphyllocalyx which is native to northern Japan. As compared to Russian subspecies, plants are different morphologically and they are adapted to more moderate climates. “Haskap”, the original Ainu name for this berry, is used by the Japanese industry and I think it appropriate to retain this unique name to distinguish this superior, new berry from the various ill-adapted blue honeysuckle plants currently in the North American nursery trade. In 2000, we collected seeds in Hokkaido from Japanese haskap selections. As far as I know, this was the first introduction of this subspecies to North America.

Haskap characteristics

Plants are long-lived, deciduous shrubs to about 6 feet in height and width, similar in growth habit and size to highbush blueberries. Growth habit may be very upright to very spreading or drooping. Flowers are cream-colored to light yellow and although small (about 3/4″ long) their abundance creates an attractive flowering shrub in spring. Flowering is early; it occurs during March to early April in Corvallis, a period during which frosts are common. The Japanese claim that flowers at full bloom can withstand to about 15º F without damage, so spring frost damage should not be a problem. Plants are primarily self-incompatible; that is, they will not set fruit with their own pollen so, in order to obtain good crops, it is necessary to plant two different cultivars for cross-pollination. Bees are the main pollinators, especially bumble bees and blue orchard (or mason) bees that fly at lower temperatures than the less important honeybees.

Fruits mature very early, before or with early strawberries. In Corvallis, harvest occurs throughout May and early June. Generally, fruits on a given bush do not mature at the same time, so there may be an extended harvest period, necessitating multiple harvests. However, on some bushes the first fruits to mature remain on the bush until all others are ripe enough, so a single harvest may be possible, an important feature for mechanical harvesting.

Among the seedlings, fruits vary considerably in all traits. Fruit color is basically blue with a whitish bloom, similar to that of blueberries, although some are somewhat reddish. Size varies from 0.5 gm to 2.0 gm per berry. Fruit shapes are rarely round; they are more elongate, varying from oval, ovate, oblong, to cylindrical. Fruit texture varies from very soft and juicy to firm enough to hold up well in storage for at least 2 weeks. There may be up to 20 seeds per fruit, but these are small and soft so not noticeable when eating fruits.

Flavors are much more pronounced and mostly more tart than blueberries, so their best use will be in processed products. However, several seedlings among one progeny have fruits that, although small in size, are mild enough to enjoy eating fresh. The unique flavors contribute to excellent, high-value processed products, as already demonstrated by the Japanese. High vitamin C content (up to 70 mg/100gm) has been reported in Japan. Until now, we have not observed any pest or disease problem that would require pesticides. Propagation is by either hardwood or softwood cuttings. Seed germination has been high, 65-90%, and no stratification is necessary. In several tests, seeds planted directly after harvest had the same high germination rate as those stratified for 2 months.

The Haskap breeding program

The objective of this program is to develop superior cultivars that will provide the basis for the development of a new berry crop for the northwest. We are searching for two types of cultivars; those suitable for commercial farms and those adapted for home gardens or small U-pick farms. For commercial production, cultivars must be suitable for mechanical harvesting: bush shape must be upright, berries on a given bush should mature at the same time or early maturing fruit remain on the bush until all are mature to enable a single harvest, fruit attachment to pedicel should be strong enough to retain fruits until harvest, but loose enough so they fall with shaking, and fruits must be firm enough to withstand shaking and catching. For home gardens and small U-pick farms, desirable traits are moderate bush vigor, large fruit size for ease of hand-harvesting, attractive appearance for local fresh sales, mild taste for fresh consumption, or tart for processing, and firm enough to hold up well for 2 weeks in cold storage. An extended harvest period is desirable to spread the fruiting season and the harvest labor.

The current haskap evaluation and breeding program began with planting the newly introduced seeds in 2001 in Corvallis and in Sandpoint, ID. My collaborator, Prof. Danny Barney at the Research and Extension Center of University of Idaho, has comparable plantings in a colder climate. In each of the four succeeding years, additional seeds have been planted and seedlings evaluated in both locations. For each plant, observations are recorded on vegetative and reproductive traits, such as bush vigor and growth habit, dates of flowering, estimated flower abundance, estimated yield, and harvest weight. After harvest, fruit traits such as size (typical 10-berry weight), shape, attractiveness, firmness, and taste evaluations are recorded.

Selections are made in the second and third year in field. Many are rejected at this time, several are kept to evaluate another year, and a few of the very best are propagated. Two, or four, of each selected clone are placed in a preliminary advanced trial plot for further consideration as parents in the breeding program or as potential cultivars. In 2003, the actual breeding program began with controlled cross-pollinations, using the most promising plants as parents. About 4,000 hybrid seedlings derived from crosses made in both 2003 and 2004 will be fruiting for the first time this year. With both parents selected for desirable traits, this population is expected to reveal superior seedlings as compared to previously grown open-pollinated seedlings.

Advanced Trial Plots

This year, several promising selections were propagated by cuttings and a few of each distributed to grower-cooperators for further evaluation in several sites in Oregon, Washington, California, and one in North Carolina. This input will assist in identifying the most widely adaptable and best performing selections. Next year, we are establishing replicated trial plots with 9 of the most promising selections at the North Willamette Branch Experiment Station in Aurora, OR, at Idaho Research and Extension Centers in Sandpoint, ID, and in Parma, ID, and possibly at Washington State Branch Experiment Station in Mt. Vernon, WA. After these comprehensive evaluations are completed within a few years, we hope to identify a few selections that are worthy of naming and release as cultivars for nurserymen to propagate and distribute.


  1. Plants appear to be well adapted to both the Willamette Valley, Oregon and to the colder region of Sandpoint, Idaho.
  2. Plants grow vigorously and produce good crops each year at these sites

3 Among our breeding plots the large amount of genetic variability for all traits sought indicates good potential for rapid selection advance.

  1. With identification and testing of superior forms, there is excellent potential to develop cultivars that will provide the basis for a new berry crop.
  2. Selected haskap cultivars will provide a new easy-to-grow berry that will extend the fruit season for home gardeners and small U-pick farms.
  3. If the absence of pests or diseases persists, this berry offers the possibility of successful organic culture.
  4. With the unique, new flavors we expect that haskap will fill a niche market for high-value specialty products.