GARDENING QUESTIONS Winter pruning of raspberries is OK

Question: It is now January. I was told to prune my raspberry bushes earlier this year. What do I do?

Answer: Late winter is a good time to prune raspberries. You can prune fall-bearing plants back to the ground anytime during the dormant season. They produce berries on new growth, and this type of pruning results in a larger and earlier fall crop.

Summer-bearing raspberries are managed differently. They produce fruit on second-year canes. Removing the canes that bore fruit right after the summer harvest helps reduce the risk of insect and disease problems. If this was not done, remove those canes that bore fruit this past summer when doing your winter pruning.

Thin the remaining canes to four or five healthy canes per foot within each row. This is usually sufficient. You can, if desired, reduce the height by no more than one-fourth, as most berries form 2 feet and higher on the plant. More severe pruning means less fruit next summer.

Winter-hardy fall-bearing raspberries, often sold as everbearing, produce their summer crop on second-year canes and fall crop on new growth. Prune like fall-bearing if you only want a fall crop. Prune like summer-bearing if you want a summer and fall harvest. The University of Wisconsin Extension publication A1610, “Growing Raspberries in Wisconsin,” has helpful pruning diagrams. It is available for free on the Internet at learningstore.uwex.edu/ (search A1610).

Q: This fall the leaves didn't quite have a chance to change color and then dry up before the cold hit, leaving many dead on the branches. Does this breaking of their cycle hurt plants?

A: Some plants like beeches and some oaks hold onto a portion of their leaves for the winter. This phenomenon is known as marcescence, the retention of dormant or dried-up plant parts like leaves.

Environmental factors like unusually warm fall weather followed by a sudden drop in temperatures often results in leaf retention on plants that normally shed their leaves in fall.

In fall, leaves on most deciduous plants form an abscission layer. These thin-walled cells break in fall, allowing the leaves to drop from the tree. Unusual fall weather or other stress factors can kill the leaves before the abscission layer is fully formed, so the leaves remain on the tree. These leaves eventually will drop over winter or in spring as new growth emerges.