Thunderhead Blackberry is a groundbreaking primocane-fruiting cultivar developed by the USDA-ARS breeding program in Oregon, combining the vigor of a thorny parent with the thornless characteristics of 'Prime-Ark® Freedom' to create something entirely new. Hardy in zones 6 through 9, this mid-sized shrub reaches about 4 feet tall and produces medium-sized, glossy, firm berries with exceptional flavor and notably small seeds. It delivers high yields on vigorous canes, making it a smart choice for hot-climate gardeners looking for a truly novel variety.
Full Sun
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6-9
48in H x ?in W
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High
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Thunderhead represents the first successful cross of its kind from a controlled USDA breeding program, combining strong plant vigor with the convenience of thornless canes. The berries themselves are distinctive: medium-sized with a glossy finish, firm enough to handle well, and packed with flavor that goes well beyond typical blackberry character. Small seed size is a real advantage for fresh eating, setting it apart from many traditional blackberry varieties where seeds can dominate the eating experience.
As an edible blackberry, Thunderhead is grown for fresh consumption, where the small seeds and firm texture make each berry particularly enjoyable to eat out of hand. The high yields and excellent flavor also suit it to preserves, jams, and other culinary preparations where the berry's quality and firm structure shine.
No timeline data available yet for this variety.
Pick berries when they develop a deep black color and feel slightly soft to the touch, indicating full ripeness and peak flavor. The glossy, firm berries should release easily from the cane when ready. Harvest regularly throughout the fruiting window to encourage continued production and prevent overripe fruit from dropping.
As a primocane-fruiting blackberry, Thunderhead produces fruit on new canes in the first growing season. After harvest, remove the canes that fruited to the ground, then select and retain the strongest new canes for next season's crop. This renewal pruning keeps the plant manageable at its mature height of around 4 feet and encourages the vigorous growth the variety is known for.
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“Thunderhead emerged from a carefully controlled crossing conducted by USDA-ARS breeders in Oregon, pairing the thorny primocane-fruiting blackberry ORUS 4355-2 with the thornless primocane-fruiting 'Prime-Ark® Freedom' (USPP34,914). This deliberate breeding effort aimed to combine the best traits of both parents, resulting in the first cultivar of its specific genetic combination. The variety represents a significant milestone in blackberry development, offering growers something that hadn't existed before.”