Answer: 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 year?s 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.
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