Rubus canadensis

Thornless Blackberry

Thornless Blackberry
Photo courtesy USDA Plants Database
and James L. Reveal

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Rubus, from the Latin, "bramble, briar"
  • canadensis, from the Latin, "of Canada"
  • Common Name, from
  • Other common names include Canadian Blackberry, Smooth Blackberry


  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Magnoliopsida, the Dicotyledons
      • Subclass Rosidae, the Roses
        • Order Rosales, the Roses
          • Family Rosaceae, the Roses; with Amelanchier (Juneberries), Aronia (Chokeberries), Crataegus (Hawthorns), Malus (Apples), Physocarpus (Ninebark), Potentilla (Cinquefoils), Prunus (Cherries & Plums), Rosa (Roses), Sorbus (Mountain Ash), and Spiraea (Spirea)
            • Genus Rubus, the Brambles, with Dewberries, Raspberries, and Thimbleberry.
  • Taxonomic Serial Number: 504842
  • Also known as Rubus argutus var. randii, Rubus besseyi, Rubus forestalis, Rubus illustris, Rubus irregularis, Rubus laetabilis, Rubus millspaughii, Rubus randii


  • A deciduous, erect or arching, thicket-forming shrub to 10' in height.
  • Leaves compound, alternate, 4"-8" long.
  • Flowers white, numerous, borne in clusters of up to 25.
  • Fruit an aggregate of small drupes, each containing a single hard-pitted nutlet.
  • Rhizomes about 3"-4" below the surface.



  • Newfoundland to Ontario, along the Atlantic Coast south to Georgia and inland to Kentucky and Tennessee.


  • Shade intolerant
  • Common understory species in open deciduous forests, on mountain ridges, and in disturbed areas.


  • Favored by fire; even severe fires provide conditions where blackberry can establish or increase. Like all blackberries, well adapted to colonize burns.
  • Burning typically stimulates sprouting. Root crowns and rhizomes are primarily in the mineral soil, a morphological trait that favors high rates of survival following fire. Fire top-kills plant; probably survives most fires by sprouting from rootstocks and/or rhizomes.


  • Trees:
  • Shrubs: Moose Maple (Acer spicatum), Juneberries (Amelanchier spp.), Beaked Hazel (Corylus cornuta), Red Elderberry (Sambucus racemosa ssp. pubens)
  • Herbs:
  • Ground Covers:
  • Mammals: Game birds, songbirds, raccoons, chipmunks, and squirrels eat fruits. Deer and rabbits browse leaves and stems. Creates nearly impenetrable thickets where birds, rabbits, and other animals hide.
  • Birds: Colonies of blackberry are common nesting sites for small birds.



  • Fruit of all blackberries used to make desserts and sweet liqueurs.


  • Reproduces from seeds, by sprouting from rhizomes and the root crown, and by layering. Vegetative propagation primary source of development of dense colonies.
  • Seed dispersal by birds and animals that eat the fruit.


  • By seed, following stratification. Most Rubus seeds require, as a minimum, warm stratification at 68 º to 86 º F for 90 days, followed by cold stratification at 36º to 41º F for an additional 90 days. These conditions are frequently encountered naturally as seeds mature in summer and remain in the soil through the cold winter months.
  • Division most successful method.


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Maintaining openings in the overstory is the key to promoting thornless blackberry because invading trees and shrubs quickly shade it out. Can be encouraged or rejuvenated by removing overhead shade, mowing, light burning, or deep cultivation.
  • Moderately sensitive to ozone.



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Last updated on 8 March, 2006