Blackberries are popular fruits found in gardens and natural landscapes. Understanding their growth cycle is helpful for gardeners and anyone interested in how these plants develop.
Understanding Blackberry Growth Habits
Blackberry plants grow via canes, long stems emerging from the plant’s crown. Individual canes are biennial, living for two years. There are two types: primocanes, which are first-year growth, and floricanes, which are second-year canes that bear fruit.
Blackberry varieties exhibit different growth habits: erect, semi-erect, and trailing. Erect types, like ‘Natchez’, are self-supporting and form hedgerows, often benefiting from summer pruning to encourage branching. Semi-erect varieties, such as ‘Chester’ and ‘Triple Crown’, typically grow as clumps and benefit from trellising for support. Trailing blackberries, often thornless, have long canes that require trellises or other structures to keep them off the ground.
The First Year Primocane Stage
Primocanes emerge from the plant’s perennial crown or root system, typically in spring. These new shoots exhibit rapid vegetative growth throughout their first season, establishing a robust structure by growing in length and developing leaves, stems, and branches. During this initial year, primocanes generally do not produce flowers or fruit; their primary function is to store energy for the following year’s production. However, some newer primocane-fruiting varieties can produce a crop on their tips in late summer or fall.
The Second Year Floricane Stage and Fruiting
As primocanes successfully overwinter, they transition into their second year, becoming floricanes. These mature canes are responsible for producing the season’s blackberry crop. Flowering typically occurs in the spring on these floricanes, leading to fruit development.
Blackberry fruits undergo a color transformation as they ripen, progressing from green to red, and finally to black. For optimal flavor, it is advisable to allow the berries to remain on the plant for a few days after they turn black, ensuring they become soft and sweet. After the floricanes have completed their fruiting cycle, they naturally die back, having fulfilled their purpose.
Perennial Root System and Cane Renewal
While individual blackberry canes are biennial, the overall blackberry plant is perennial. The established root system and crown persist year after year, often for a decade or more. This allows for continuous fruit production. Each year, the root system sends up new primocanes, replacing floricanes that die back after fruiting. This ongoing cycle ensures the plant consistently produces a fresh set of fruit-bearing canes each season.
Seasonal Cycle and Dormancy
The blackberry plant’s annual cycle integrates cane growth with seasonal changes. New primocanes emerge in spring, growing vegetatively throughout the summer months. During this time, floricanes from the previous year are simultaneously producing fruit. As autumn approaches, the plant prepares for winter.
Blackberries enter dormancy during colder months, a natural response that allows the plant to conserve energy. Though above-ground growth slows or halts, the root system remains active. This period of cold allows the plant to prepare for renewed growth in the spring, when the cycle begins anew with fresh primocanes and the continued development of overwintered floricanes.