The blackberry, a fruit from the genus Rubus, presents a challenging question to anyone who has foraged for the wild berries. The short answer is that while many people associate these plants with painful, sharp projections, not all blackberries have them. The presence of these structures depends heavily on whether the plant is a wild native species or a modern, cultivated variety developed for gardens and commercial production.
The Straight Answer: Yes, But It Depends
The vast majority of blackberries found growing naturally in fields, forests, and along roadsides are heavily armed with sharp structures along their canes and leaves. These wild varieties have retained this evolutionary trait because it offers a distinct survival advantage against herbivores. This is the classic image of the blackberry bramble that has caused countless scratches to foragers.
Modern agricultural science has changed this reality for home gardeners and commercial growers. Plant breeders have successfully developed many varieties that are completely thornless, making harvesting and maintenance significantly easier. These cultivated plants are selected for both their lack of thorns and their improved fruit quality.
Understanding Blackberry Thorns (Prickles)
Botanically speaking, the sharp projections on a blackberry plant are correctly identified as prickles, not true thorns. True thorns are modified woody branches containing vascular tissue. Blackberry prickles, in contrast, are outgrowths of the plant’s outer skin (epidermis) and lack this internal vascular system.
Because they are only extensions of the surface tissue, prickles are generally easier to snap off than true thorns, though they are still rigid and sharp. These pointed structures typically line the length of the plant’s canes, but can sometimes be found on the underside of the leaves. Their purpose is a defense mechanism, serving as a physical barrier to deter large herbivores and pests from eating the leaves and fruit, protecting the plant’s ability to reproduce.
Thornless Varieties and Cultivation
The development of thornless blackberries began with the selection of natural genetic mutations in the wild. Breeders propagated plants that exhibited this smooth-caned trait, which is desirable for ease of harvest and safety. Most modern thornless cultivars trace their lineage to these initial mutations, which were then refined to improve fruit flavor and plant vigor.
Popular thornless varieties often have an upright or semi-erect growth habit, making them easier to manage in a garden setting. The ‘Navaho’ blackberry is an erect variety known for its sweet flavor and high sugar content. Other reliable cultivars include ‘Arapaho,’ prized for being one of the earliest ripening thornless berries with a compact form, and ‘Ouachita,’ which offers high yields of large fruit with a good balance of sweetness and tartness. Modern breeding programs have eliminated the trade-off where older thornless types had less complex flavor.
Safe Handling During Harvest and Pruning
Even with the availability of thornless varieties, many gardeners and foragers still encounter thorny blackberry brambles. Protecting yourself requires simple precautions. Always wear thick, durable gloves, such as leather rose gloves, that extend up the forearm to prevent scratches.
When pruning the biennial canes, long sleeves and sturdy pants are necessary to shield your skin. Pruning is typically done after the floricanes—the second-year canes that have finished fruiting—are done for the season. These spent canes will die and must be removed to encourage new growth. Controlling these thorny canes and the long, arching primocanes must be done with caution to minimize injury and maintain plant health.