Smooth Blackberry (Rubus canadensis)

Rubus canadensis (Smooth Blackberry) is a thicket-forming, deciduous shrub with long, slender, arching canes free of prickles and spines. The inflorescence is a cluster of up to 25 flowers. The fruit is an aggregate of many small drupes, each of which contains a tiny nutlet. The plant reproduces by seed, by sprouting up from the rhizome, and by layering. The stems can grow one meter (1.02 m) in height in under two months.

I. Appearance and Characteristics

Rubus canadensis is a North American species of flowering plant in the rose family known by the common names smooth blackberry, Canadian blackberry, thornless blackberry and smooth highbush blackberry. It is native to central and eastern Canada (from Newfoundland to Ontario) and the eastern United States (New England, the Great Lakes region, and the Appalachian Mountains).

This rhizomatous shrub forms thickets up to 2 to 3 meters (7–10 feet) tall. The leaves are deciduous and alternately arranged, each measuring 10 to 20 centimeters (4-8 inches) long. The inflorescence is a cluster of up to 25 flowers. The fruit is an aggregate of many small drupes, each of which contains a tiny nutlet. The plant reproduces by seed, by sprouting up from the rhizome, and by layering. The stems can grow one meter (40 inches) in height in under two months.

Rubus canadensis grows in many types of forested habitat, as well as on disturbed sites. Associated plants may include mountain maple (Acer spicatum), serviceberry (Amelanchier spp.), hobblebush (Viburnum alnifolium), scarlet elder (Sambucus pubens), common blackberry (Rubus allegheniensis), beaked hazel (Corylus cornuta), southern mountain cranberry (Vaccinium erythrocarpum), minnie-bush (Menziesia pilosa), and rosebay (Rhododendron catawbiense).

Many types of animals feed on the fruits and foliage of this shrub. The thickets provide cover and nesting sites.

The fruits of this plant provided food for Native American groups, who also used parts of the plant medicinally at times.

Smooth Blackberry (Rubus canadensis)

II. How to Grow and Care

Smooth blackberry is generally an easy plant to care for, thriving in a variety of soil types as long as they are well-draining. Special care points include regular pruning to maintain its shape and manage its spreading habit. It is important to monitor for pests, especially aphids and spider mites, which can be common nuisances for smooth blackberry.

Sunlight

Although you can find some Rubus species under the forest canopy, smooth blackberry loves sunlight. Full sun or partial shade (6-8 hours of sunshine) will be the best for it to thrive. Avoid too crowded bush to allow ample sunlight and air movement, which will prevent your plant from diseases.

Temperature

As a large genus, Rubus has a wide distribution range which means you are always likely to find a proper species or cultivar that grows well in your garden. Generally, Rubus species flourish in temperate zones, and adaptable to slightly harsh conditions. Select cultivars that may thrive in your garden, thus the preferable climate will encourage them to bear more edible fruits. Smooth blackberry prefers moist to slightly dry conditions, so it is important to avoid waterlogging.

Watering

Smooth blackberry thrives in environments that mimic its native woodland settings, where it benefits from the periodic rainfall and rich organic matter. This species is accustomed to moderate moisture levels and displays a preference for consistent humidity without being waterlogged. It requires watering once every three weeks, aligning with its ability to tolerate short dry spells. Typically grown outdoors due to its natural habitat, smooth blackberry has an affinity for well-draining soil which plays a pivotal role during its active growing season by maintaining optimal moisture without becoming soggy.

Soil

Smooth blackberry is not picky about soil, as long as the soil is slightly acidic and well-drained. The ideal soil pH range for it is 5.5–7 while a few species and cultivars of Rubus may tolerate slightly alkaline soil as well. Rich loamy soil mixing with some sandy soil can be a good option. Always remember to avoid the heavy clay soil because it can become soggy easily. Hilled soils that promote drainage can also be taken into consideration, instead of wet, flat field.

Fertilizing

To ensure optimal growth for smooth blackberry, apply balanced nutrition fertilizers (like 10-10-10) in early spring to kickstart growth, and high-nitrogen fertilizer before flowering. Frequent application is unnecessary; once at the start of the growing season suffices. Use fertilizers sparingly, as too much can harm smooth blackberry. During fruiting, it’s crucial to maintain adequate fertilization to support vigorous fruit production. Adjust fertilizer use as smooth blackberry’s growth and fruiting phases dictate. Practical tip: Apply fertilizer around the drip line, not directly on stems or roots, to prevent burn.

Planting Instructions

Generally, smooth blackberry is planted with saplings that are easily purchased from nursery or gardening store. Avoid smooth blackberry collected in the forest as diseases are a big problem for wild Rubus.

Plant your smooth blackberry in winter or early spring in your garden. Smooth blackberry grows wild where there is much sunlight from above and a wealth of leaf litter, otherwise known as mulch or organic matter in the soil below. Because of this, your planting site is recommended to have ample sunlight and you should have organic matter such as grass clippings readily available. Keep your plants far away from any wild brambles to keep them healthy.

Also, plant your smooth blackberry in separate rows. The optimum spacing can be achieved by creating rows about 3 m apart with plants 60 cm apart within each row. Set a trellis on each side and tie the canes onto the trellis line or wire.

Smooth blackberry will spread both rapidly and at long distances. If you do not want it everywhere in your garden, regularly prune it or grow it in containers. You are recommended to find a prickle-free and small variety to plant in pot, which may be handy for you. Use a shallow but large container for it because its roots spread shallowly outward. Potting soil and sunny place are standards for smooth blackberry.

Pruning

Pruning is important for smooth blackberry growers. Prune all canes that bore fruit this year down to the bottom right after harvest. All first-year canes should be cut about half to stimulate lateral growth from the side every late winter or early spring. Remove all suckers and trim overcrowded canes. Smooth blackberry grown in patches must be pruned to ensure that individual canes are not touching to avoid disease infections. Be sure to remove any thinned or pruned canes from the field because old canes left on the ground can harbor disease.

Propagation

Smooth blackberry thrives through cuttings, a practical method due to its vigorous rooting abilities. Begin by selecting healthy, non-flowering shoots in late spring or early summer. Cut a 4 to 6-inch section and remove leaves from the lower half. Dip the cut end into rooting hormone and plant in a well-drained rooting medium. Maintain consistent moisture and high humidity around smooth blackberry until roots establish for a successful proliferation of this robust berry producer.

III. Harvesting and Storage

Taste the fruit and it will tell you when it is time to harvest. Ripe fruits will be sweet and juicy. If they are still sour or tart, let them ripen a bit longer. Usually you can start harvesting from mid-summer till mid-fall, according to varieties. You should harvest the fruits when all dews or raindrops are dry to prevent molds. They have a short shelf life, so refrigerate them after harvest without washing. As for some sour species, process them into delicious jams or jellies.

«
»