Caneberry plants consist of perennial crowns and root systems and biennial vegetative shoots, or canes. The vegetative shoots of caneberries are referred to as primocanes and the flowering and fruiting canes are referred to as floricanes. Normally, these stages of cane are separated by one growing season; however, more contemporary varieties of caneberries grow vegetatively and flower and fruit in one year. These newer varieties are known as primocane-fruiting cultivars. In addition, in many areas of California caneberries may not pass through visually distinct growth stages because of the lack of a winter dormant period; they just progress from vegetative stages into reproductive growth.
Regardless of the age of the cane, once flowering begins, productive caneberry cultivars can be managed for an extended harvest on primocanes or floricanes if care is taken to manage the cane canopy, foliage, flowers, and fruits with pruning, fertility, and pest management to protect them from mites, insects, and diseases. Careful irrigation management is also important so that plants are not stressed during critical flower and fruit development periods. Crowns and underground portions of caneberries can be susceptible to soilborne fungal diseases. In areas where drainage is limited or slow, both types of caneberries are routinely planted on raised beds to minimize disease.
Caneberry plantings can last many years, but current intensive management systems emphasize primocane fruiting cultivars planted at relatively high density that are only harvested for 1 to 2 years before the planting is replaced. While more management intensive, this production system allows more control over harvest season, yield, and fruit quality.
The initial primocanes that emerge from the crown or root grow vegetatively for a period of time that varies from several weeks to a whole year or season. They eventually convert to a reproductive growth period, usually following a winter-chilling period. Flowering then begins on terminals and laterals of the canes and they are referred to as floricanes. The period between the development of primocanes and floricanes may be a clearly differentiated period that includes chilling and defoliation as with summer-bearing or floricane-fruiting raspberries. In the absence of chilling requirements, the plants may fruit on the end of primocanes in fall-bearing, everbearing, or primocane-fruiting raspberries.
The primocane-fruiting trait allows more flexible cropping options: only primocane fruit is harvested, or only floricane fruit is harvested, or both types are harvested, depending upon the cropping system and growing conditions. In a cropping system where only primocane fruit is harvested, the plants are mowed to the ground each season and fruit is harvested on the ends of the primocanes the following fall.
Intensive production systems tend to keep rows narrow to control cane vigor and competition. Efficient management of a raspberry planting involves managing the entire hedge or crop of canes to maximize fruit production and quality. Typically, a high yield of larger fruit comes from vigorous canes with healthy foliage.
Trellising of raspberries is primarily done to keep canes upright under a heavy fruit load and to improve air circulation around the outer canes and to facilitate spray operations when needed. The trellis arrangement can also be used to manipulate light interception and to improve air circulation in the middle part of the canopy.
Each spring new canes emerge as basal shoots from crown or as "suckers" from underground spreading horizontal roots. The vegetative canes of the raspberry plants are relatively short, erect and self-supporting. These canes eventually form a solid row or hedge, depending upon their management. Raspberry canes are typically spiny with short-to-medium spines varying down to fine spines that approach spine-free. The spines or thorns of raspberries are not as serious of a management issue as with blackberries.
Cultural practices are directed toward encouraging an optimum density of canes and controlling twospotted mites and other insects and diseases that threaten canes and foliage.
Blackberries exhibit similar growth characteristics to those of raspberries but do not sucker and spread as freely so they tend to be managed as individual plant units. Plants are pruned to maintain an optimum number—typically 4 to 6—canes per crown and further pruned one or more times to limit their height. Blackberries are typically, though not always, trained on to a single, narrow trellis with two wires (one at 1 ft and one at 3 ft in height) to control the cane orientation, allow adequate air circulation, light interception, and to enable spraying or other cultural practices as needed.
Traditionally, there have not been primocane-fruiting blackberry varieties available and the initial harvest has required an extended growth period to pass through a primocane development periods before flower and fruiting occurred. In temperate climates, blackberries are harvested the second season from planting. The first primocane-fruiting blackberries, however, are now available and with time, more cultivars should become available that will enable the harvest of blackberries in more varied cropping systems and environments. Special pruning systems are being developed to optimize the growth and production characteristics of primocane-fruiting blackberries.
There are currently diverse types of blackberries available that are thorny or non-thorny, erect, semi-erect or trailing, and early to late maturing. Similarly, the plant vigor, fruit size, flavor, seediness, or firmness may also vary. Each of these characteristics may play a role in selecting a variety for a specific production environment or harvest regime.