Smoothstem
Date: 2021-06-25, updated: 2023-03-09
Old and proven very vigorous high-productive trailing blackberry cultivar
Rubus subgenus Rubus Watson 'Smoothstem'
Originated from a cross of Merton Thornless x Eldorado
Variety denomination 'Smoothstem'
Plants are thornless
Bushes have trailing canes
Fruit weight is 7 g
Berries have a conical shape
Fruiting habit floricane fruiting (summer-bearing)
Flowering on floricanes starts in the second week of June
Ripening date (regular) - fourth week of July
Productivity is 20 kg per plant
Cold hardiness is excellent
Country of origin United States
Current status - obsolete or rarely used
Recommended replacement - Columbia Sunrise
Smoothstem is one of the old American varieties of thornless floricane-fruiting blackberry, selected in 1966 in USA as a cross from Merton Thornless and Eldorado. It's characteristics is very similar to Thornfree variety, because both have same parents. Plants are very trailing and vigorous, stems can achieve up to 5 m in length and up to 2 m in height. Large white (with low pinkish shade) flowers appear in June. It has long harvest season - gives mature berries from late July to October. Berries of Smoothstem are big (typically 6-8 g, and up to 14 g), oblong in shape, have black color and glossy, slightly larger in size than Thornfree. Oftentimes even ripen berries have sour taste. If such berries have been leaved on bushes, after few days with good weather conditions they gain sugar taste, but lose glossiness. Firmness is very low, berries are juicy. Yield is great, 15-25 kg/plant when using appropriate autumn and season cropping and fertilizing.
Pests and disease resistance are normal, winter hardiness is excellent, up to minus 23 C. Smoothstem doesn't give good yield in shadow areas, but plants are sensitive to high summer temperatures, laterals with fruit can shrink, so bushes need to be sheltered from direct sun rays.
Pests and disease resistance are normal, winter hardiness is excellent, up to minus 23 C. Smoothstem doesn't give good yield in shadow areas, but plants are sensitive to high summer temperatures, laterals with fruit can shrink, so bushes need to be sheltered from direct sun rays.