Ian in Summerstown, Ontario, asks:
I have raspberries that produce in July, then a second crop in September/ October. How would you suggest I prune the canes?
Garden Making reply:
Our suggestion is to read the factsheet on “Raspberries and Blackberries for Home Gardens” published online by the Ontario Ministry of Agriculture, Food and Rural Affairs. Here is a link to the factsheet: omafra.gov.on.ca/english/crops/facts/99-033.htm
The section on pruning suggests the following:
Fruiting canes die when harvest is completed. Cut out and destroy these;. This prevents serious disease buildup since the sources of infection have been removed. Remove small and/or weak canes as well.
In spring, after the danger of winter kill is past, further pruning is needed to remove weak canes and dead tips of canes. Keep 15 canes per 40 inches (1 m) length of row. Remember to keep the rows narrow. Leave the strongest and most vigorous canes evenly spaced in the row. Shorten tall canes to 53 inches (135 cm) for convenient harvesting.
Fall-bearing raspberries are usually grown for just the fall crop. After fruiting, all canes are removed and destroyed. The next season, a new flush of primocanes appears and bears fruit in the fall. Thinning is not usually necessary.
If two crops are desired, then fall-bearing raspberries are treated like red raspberries. After harvest, prune and destroy the portion of the cane producing the fall crop.