Wednesday, June 26, 2013

Blackberry Time: Midsummer to Early Fall

Written May 21, 2013, published in June 2013, all photos by Kathleen Sayce

Blackberries are a favorite summer fruit. There are several varieties to chose among that grow well here, including the native Pacific blackberry, introduced evergreen and Himalayan blackberries, and and several cultivated varieties (or cultivars) that were bred for heavier fruit-bearing, larger fruits, and darker, more intense flavors. These include Loganberries, Youngberries, Olallieberries, Boysenberries, and Marionberries. Why write about berries now? Fall is a good time to plant new blackberries in your garden. Their roots will establish over winter, and by next spring they will be growing strongly. 

Himalayan blackberries are in full flower by mid summer, and continue flowering until early fall; fruits stop accumulating sugar by late September.

The starting species:

Pacific blackberry grows naturally in the Pacific Northwest, and is a low-growing, sprawling vine. Fruits usually ripen in midsummer over a few short weeks, and are small and intensely flavored. Unusual among plants in the Pacific Northwest, Pacific blackberries have separate male and female plants; in botanical terms this is 'imperfect.' They also tend to have individual plants with multiple ploidy, or many more sets of chromosomes than the usual two sets. Both sexes have white flowers; males have many more flowers than females. If you look closely at the flowers, you can see either clusters of anther-tipped stamens on the male flowers, or a dense cluster of stigmas, with no anthers, on the female flowers. Male flowers also tend to be slightly larger and showier. During flowering, check plants and note the females, because these will have berries later on. 

Himalayan blackberry (Rubus armeniacus) arrived in North America in 1885, brought here by horticulturists for fruit. Once established, fruit-eating birds and other animals quickly discovered the large, juicy berries, and began spreading them around. This and most other Rubus species have plants with both sexes in the same flowers––botanists call this 'perfect' flowers. Native to Armenia and northern Iran despite the common name, Himalayan blackberries are more accurately called Armenian blackberries. This blackberry is well established in the Pacific Northwest. 

Red raspberries (Rubus idaeus) are European, and were introduced to North America for their fragrant, sweet red fruits. They are widely grown throughout the continent today. Unlike Armenian blackberries, red raspberries did not escape cultivation so easily, though this species has found its way beyond cultivation in some areas. 

Black raspberry (R. occidentalis) is native to eastern North America, and has a very fragrant black berry that is used to flavor fruit cordials, such as Chambord du framboise. It is  widely grown in North America, as well as other temperate areas around the world. 

Ripening Marionberries go from pale green to red to dark purple over a period of weeks, usually peaking in production in August, when berries ripen every day. 

Hybridizing begins:

Enter 19th Century horticulturists eager to develop vines with bigger fruit, more flavor, and larger crops. They worked all over the world to develop highly productive, disease-resistant brambles for a wide range of climates.  The genus Rubus has hundreds of species. Hybridizing is relatively easy once the genetics are aligned. The base number of chromosomes (N), or ploidy, for the genus is 7. Typical diploids are 2N with fourteen chromosomes. The highest number of chromosomes known for a Rubus is 98. Trivia (or there's a word for that):  Those who study Rubus species are engaged in batology, the study of brambles.  

Breeders in eastern North America began by selecting among native and introduced Rubus species, including red raspberries, Pacific blackberries and dewberries (eastern blackberries, yet another member of the large genus Rubus) for vines that were sturdy, with fruits that were large and flavorful, with larger crops than wild plants naturally produce. 

The starting Pacific blackberry was a female octoploid plant (N=56) named Aughinbaugh. Rubus x 'Aughinbaugh' was crossed with a selected red raspberry. Their progeny were then crossed with an eastern dewberry. In each generation, plants were selected that showed desirable traits, including vigor, tasty large fruit, and increased flowering and fruiting capacity, which all contributed to higher production and more desirable fruit characteristics. 

The 'named' plants to result from this process that are still grown today in the U.S. are Loganberries, first grown in 1883, and Youngberries, in 1905. Youngberries were bred in the southeastern US, and today are widely grown in Australia, New Zealand and South Africa, while Loganberries were developed in California, and are grown in the west and Pacific Northwest. Boysenberries were developed at the same time, and from the same progenitors.   

Meanwhile, the Willamette Valley became a prime berry growing region and local breeding focused on berries that do well in this climate. 

Loganberries and Youngberries were crossed, and the more flavorful but less productive Olallie blackberry, or Olallieberry, was selected from their progeny in 1937. Pacific blackberries were crossed again with Loganberries to produce the Santiam blackberry in the early 20th century. The Santiam blackberry was crossed with Himalayan blackberry to produce the Chehalem blackberry in 1936. 

Chehalem blackberries were crossed with Olallieberry mid century, and out of this cross came Marion blackberries, or Marionberries, a truly gorgeous, black, flavorful berry on sturdy vines. A strong grower and highly productive vine, it quickly moved into production, and is widely grown today. Notice all the names that are Willamette Valley-based: Chehalem, Marion, Olalla, Santiam. 

Ripe Marionberries are large and dark purple-black, flavorful and full of anthocyanins. 

Modern breeding continues:

This wasn't the end of blackberry breeding. The Kotata blackberry was produced in 1951 and released to farmers in 1989. Slightly earlier to fruit than Marionberries, it expands the berry-growing season in the Pacific Northwest. Batalogical research continues today on disease resistance, vigor, and improved fruit quality. Another memorable bramble may emerge from this work in coming years. 

Black raspberries also continue to be bred and selected for flavor, disease resistance and production in the Pacific Northwest. Many varieties of raspberries are grown in the Valley. 

In other climates, golden and purple raspberries, and other brambles in the genus Rubus are important fruit vines. Cloudberries, Rubus chamaemorus, grow at high latitudes; these berries are red when unripe, and turn gold when ripe. Extremely hardy, they grow above 55°N, with a few populations at high elevations down to 44°N. 

Anthocyanins and cellular health:

Highly colored berries in the genus Rubus are naturally high in anthocyanins [antho-CY-an-ins], which in plants act as photo-protective pigments, screening sunlight from cells to prevent sun damage. Anthocyanins are powerful antioxidants, and promote healthy cells in animals that eat them, as they reverse cellular damage. These compounds give berries a dark color––the darker the fruit, the higher the level of anthocyanins. Red berries have some anthocyanins; dark red, purple or blue berries have more, and black berries have the most. Similar anthocyanins are found in strawberries, blueberries, cranberries and huckleberries; and again, the darker the fruit, the higher the level of anthocyanins in its cells.

The next time you eat blackberries, or other colorful berries fresh, in pie, cobbler or cordial, you are also eating antioxidants, and promoting cellular health. Cheers!

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