Pruning Raspberries and Vine Berries
Proper pruning at the correct time of the year will result in better production of raspberries and vine berries the next year.
Soon after the last raspberries have been picked, the canes that produced berries should be removed by cutting them back to ground level. This encourages the growth of new shoots the following year. Removing and destroying the fruited-out canes will also help eliminate the spread of any insects and diseases present on these canes.
Remove only the canes that fruited. The canes that grew this summer, but did not bear fruit, are the ones that will bear next years fruit.
Some years, due to weather conditions the new growth will flower toward the tip of the canes and produce fruit which turns red in November. This late crop of raspberries seldom ripens properly and very often becomes covered with a grayish mold. This disease, if not controlled, will often carry over to the next season's fruit crop. Therefore, I suggest that this late fruit crop be removed as it develops, by simply picking or pruning the fruits or flowers as they show up.
If the new canes grow too tall, they become weighted down by the heavy tip foliage which will bend the canes almost to the ground, causing them to break off during a strong wind. Cut off only this tip growth in the fall, to lessen the chances of damaging the canes. Sometimes during the fall months, the tip foliage does not drop off like the lower leaves. These leaves should then be removed by hand or they may become a place for insects and diseases to remain until the next season.
Do not do any additional pruning until late winter. Then in January or early February cut back all canes to about 4 to 5 1/2 feet and thin out the weak canes. This winter pruning keeps the canes low for easy picking the next summer.
The vine berries, like boysenberries, loganberries, and Olympic berries, should be pruned as soon as the last berries have been picked. Remove only the vine that produces the berries. Removing and destroying the fruited-out vines will also help eliminate the spread of insects and diseases present, on the old vines.
Like the raspberry, the vines of the vine berries last for two years. They grow to their full length one season, then put out lateral growth the following season. This lateral growth flowers and produces the berries. Then the fruited-out vines are removed completely. These vine berries are very robust growers and should be tip pinched in summer, when the new growth has reached about 2 or 3 feet. This pinching encourages, new lateral growth and shortens the lengthy growth habit of these berries.
Vine berries should be supported by trellis or wire strung between posts. As the new growth develops during the late summer months, it must be tied to the supports.
Although this article features pruning of berries, it is well to keep in mind the control of insects and diseases of berries.
Most insects and diseases can be controlled by late fall and early spring applications of an all-purpose insecticide-fungicide dormant spray. It should be applied to both the vines or canes and the surrounding soil, for best control.