How to winter over blueberries and black raspberries? Pruning etc. Once heard to bury the blueberries, is that true?
The best time of year to prune blueberries is during the dormant season (typically January through early March.) No need to bury the plants over the winter-in fact, this would likely encourage rotting and decay of the bushes. You will want to mulch the soil up to a depth of 6" using Douglas Fir sawdust or a bark mulch.
Find more blueberry cultivation information in the OSU Extension publication, "Growing Blueberries in Your Home Garden".
Advice on pruning raspberries can be found in the OSU Extension publication, Growing Raspberries in Your Home Garden: "Remove the top 3 to 4 inches of primocanes during late spring or early summer. Top black raspberries (blackcaps) and purple raspberries to a height of about 3 feet. Go over the planting several times during the summer to catch all the primocanes, as they don’t all grow at the same rate. With topping, primocanes will produce lateral branches (Figure 7). When plants are dormant, remove all damaged canes. Shorten lateral branches of both types to about 11⁄2 to 21⁄2 feet. Cut unbranched canes to about 3 feet. After harvest, remove all dead floricanes."