Cross Pollination of Raspberries

Cross-Pollination

• Cross-pollination is a process in which pollen from one plant is transferred to the flowers of another, at which point the pollen fertilizes the flower and enables the reproduction of the plant. This is not a necessary process for raspberry plants, which are self-fruitful. One cane produces the pollen and flowers required for successful fertilization and the engendering of a healthy crop of raspberries each growing season. Self-fruitful plants have less genetic diversity but are more likely to be pollinated.

Benefits of Self-Pollination

• Gardeners with limited space are still able to grow a crop of raspberries on a single cane or bush due to the self-fruitful nature of raspberry plants. This reduces the amount of time and effort that needs to be expended on ensuring successful pollination each growing season and increases the likelihood that an individual plant will be productive. Self-unfruitful fruit and berry-producing plants require two or more plants, sometimes of different cultivars, before any crop is available.

Pollinators

• Although raspberries are self-fruitful, the interference of pollinators is still highly beneficial for the raspberry cane. Pollinators are insects like butterflies and bees that move pollen from one portion of the plant to another in search of nectar; this increases the likelihood of fertilized flowers and a healthy crop. For this reason, it is important to avoid pesticide sprays while the raspberry plant is in bloom. Chemicals do not discriminate between harmful insects like aphids and helpful ones like bees.

Cultivars

• Since raspberries do not cross-pollinate, choosing an individual cultivar ensures that the raspberries produced each season will be of that cultivar. Different variations of raspberries grow well under individual gardening conditions and offer different berry types. For example, liberty and brandywine raspberries produce their berries in the summer, white heritage plants put out berries later in the growing season. Self-fruitful raspberry plants make choosing a variety of cultivars or an individual plant an easier task, since cross-pollination is not a necessary concern.