Columbia Star blackberry variety

Rating [ 4.1 ]

Very high-quality, high-yielding, machineharvestable, thornless trailing blackberry with firm, sweet fruit

Botanical designation

Rubus subgenus Rubus Watson 'Columbia Star'

Originated from a cross of

Originated from a cross of NZ 9629-1 x ORUS 1350-2

Variety denomination

Variety denomination - 'Columbia Star', tested as ORUS 3447-1

Plants are

Plants are thornless

Bushes have

Bushes have trailing canes

Fruit weight is

Fruit weight is 7 g


Berries have a conical shape

Fruiting habit

Fruiting habit - floricane fruiting (summer-bearing)

Flowering on floricanes starts in the

Flowering on floricanes starts in the second week of May

Ripening date (regular) -

Ripening date (regular) - fourth week of June

Productivity is

Productivity is 7 kg per plant

Soluble solids

Soluble solids - 12.8%


Acidity - 1.6%

Cold hardiness is

Cold hardiness is good

Heat tolerance is

Heat tolerance is high

Country of origin

Country of origin - United States


Patent US PP 25,532 P2 dated May 11, 2015

Current status

Current status - cultivated (actual)

Columbia Star is a thornless, trailing blackberry cultivar from the U.S. Department of Agriculture - Agricultural Research Service (USDA-ARS) breeding program in Corvallis.
Columbia Star is the first thornless blackberry to be released with the Lincoln Logan source of thornlessness other than the original Lincoln Logan and Waimate that have Logan-type fruit and Marahau that has Boysen-type fruit. A main goal of the breeding program has been to develop a thornless blackberry with high yields and with fruit quality similar to Marion blackberry. Fresh fruit of Columbia Star are rated as having better firmness than either of the current industry standards. Although not yet evaluated in commerce, Columbia Star fruit have sufficient firmness for local fresh market sales, but it is not certain whether firmness would be sufficient for wholesale fresh shipping.
Fruit color was rated similarly to Black Diamond fruit and more black than those of Marion. Columbia Star and Marion are rated similarly for fruit texture and flavor as fresh fruit and both are considered better than Black Diamond. For flavor, Columbia Star has the highest rating, comparable to Marion and better than Black Diamond. Black Diamond has become the industry favorite for its yield, machine harvestability, and generally good fruit quality but many are of the opinion that its flavor could be better.
Average fruit weight is about 7 g. Average yield is about 7 kg per plant. Columbia Star ripens in the early midseason (at the beginning of July) for trailing blackberries and over 1 month earlier than Chester Thornless semi-erect blackberry. Within the trailing cultivars, Columbia Star harvest started as early as Black Diamond, a few days ahead of Marion, but reached the midpoint of harvest 5 days ahead of Black Diamond and 3 days ahead of Marion (from the beginning of July to the end of July). Columbia Star cultivar is vigorous, comparable to Marion, and the floricanes and primocanes are more vigorous than Black Diamond.
Columbia Star nuclear stock has tested negative for Tomato ringspot virus, Tobacco ringspot virus, Apple mosaic virus, Prunus necrotic ringspot virus, Cherry leaf roll virus, Raspberry ringspot virus, Arabis mosaic virus, Tomato black ring virus, Strawberry necrotic shock virus, Raspberry bushy dwarf virus, and Tobacco streak virus by enzymelinked immunosorbent assay and has tested negative for Raspberry leaf mottle virus, Raspberry latent virus, Rubus yellow net virus, Blackberry yellow vein associated virus, Blackberry virus Y, and Blackberry chlorotic ringspot virus in reverse transcription–polymerase chain reaction assays.
Winter hardiness is about minus 17 C.
Table 1. Yield and average berry weight at Oregon State University’s North Willamette Research and Extension Center (planted in 2009)
Cultivar Berry weight, g Yield, kg/plant
2011 2012 2013
Columbia Star 7.6 7.8 6.17 8.52
Black Diamond 6.0 7.32 2.18 3.03
Marion 5.5 6.71 4.95 5.12
Table 2. Subjectively evaluated fruit quality traits for Black Diamond, Columbia Star and Marion blackberries (planted in 2009, scale from 1 to 9, where 9 is the best expression)
Cultivar Columbia Star Black Diamond Marion
Firmness 7.6 6.7 4.1
Color 8.3 8.0 7.4
Shape 8.5 8.3 5.3
Texture 8.3 6.8 8.1
Flavor 8.1 6.4 8.4
Table 3. Soluble solids, pH and titratable acidity of fruit for Columbia Star, Black Diamond, Marion and Chester Thornless varieties (2011 - 2013 years)
Cultivar Soluble solids, % Titratable acidity, % pH
Columbia Star 12.74 1.54 3.19
Black Diamond 10.28 1.22 3.38
Chester Thornless 11.69 1.05 3.28
Marion 12.57 1.56 3.21
Table 4. Harvest season (avg. from 2011 - 2013)
Cultivar Ripening
First (5%) Peak (50%) Last (95%)
Columbia Star July 3 July 12 July 24
Black Diamond July 3 July 17 July 26
Chester Thornless August 5 August 28 Sept. 25
Marion July 8 July 15 July 24

How to cultivate blackberry

How to cultivate blackberry Columbia Star?

1. Include annual preemergence and postemergence herbicide applications;
2. Include annual spring nitrogen (N) fertilization (about 78 kg/ha) using ammonium nitrate (NH4NO3);
3. Postharvest removal of floricanes;
4. Sprinkler irrigation apply weekly during the growing season;
5. Training of primocanes to a two-wire-trellis;
6. A single application of liquid lime sulfur (94 L/ha) each spring at budbreak for control of anthracnose;
7. Use sun shelters.
Diseases resistance

What diseases is blackberry Columbia Star resistant to?

Columbia Star has very good resistance to diseases such as Rosette or Double-Blossom
Diseases susceptibility

What diseases is blackberry variety Columbia Star vulnerable to?

Useful Growing Guides

Useful Growing Guides:

Columbia Giant
Previous variety
Columbia Sunrise
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Reviews of the variety Columbia Star

Review from [DREW51]

Last year a few of us went in on an order. As time went on some reported good growth, but mine were just kind of sitting there. But by the end of the year mine took off and I didn’t even notice. Yesterday I was tying the canes up from being covered in leaves. Well the plant had 9 canes! Holy Moly! Three rooted themselves! I kept one and destroyed the other two. Technically I’m probably required to destroy all but a good case of mother nature can be argued here. I didn’t intend to root any (the plant is patented).
Trying to put my wyeberry, boysenberry and tayberry canes on the trellis was futile as I kept braking huge pieces of cane off trying to move them. I’m going to have to leave them on the ground. I gave up! Plus the things are so thorny! Yikes! The thorns catching on everything too.
Whereas Columbia Star remained very flexible and was easy peasy to put on the trellis! Removing the leaves was a problem, but just pulling Columbia Star out of them was easy, not so with the others. I probably lost 50 berries yesterday trying to move the others.
I hope it tastes as good as they say, as this thornless flexible bramble is super easy to work with. I may scrape the other trailing types and just keep this one, Black diamond is similar, but the canes looked more damaged, and were not as flexible, although also thornless. Not as productive either with only 4 canes. Like Columbia Star it is a new plant and this is the first winter.
I will keep them all and experiment and see if I can find ways to work with the others. Overall though Columbia Star is a star I’m really happy to have this one!
I need a blackberry that has the complex raspberry-blackberry hybrid taste. Can take -19F temps and still be productive. Or can easily be protected. And is easy to work with. So far only Columbia Star meets my needs. The uprights are hard to protect, the other trailing are not flexible enough, and are turning out to be hard to work with. Any suggestions here welcome! Nothing is meeting my needs except Columbia Star.
One good observation was that burying the trailing types in leaves did protect them. Canes are green, some even have whole leaves.
On the uprights spraying them with wilt-stop, putting burlap around them (The burlap was not on them that well) also seemed to have protected them. All canes exposed look dead, but where I wrapped them with burlap look green and alive. Even though it was a very poor job of wrapping. A definite difference in color where wrapped.


Columbia Star is an exciting, early season blackberry that delivers an excellent combination of superlative flavour with very high yields.

Review from [MosBerry]

This cultivar grew in a pot. Very weak plant. Constant chlorosis, even with regular fertilizing. Extremely poorly tolerate to waterlogging. Canes are not thick, leaves are soft and easily affected by diseases and a lot of pests. Leafroller and spider mite very like this soft leaves.

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