Fruits: If you didn’t prune your raspberries in fall, you can do so now. It helps to know if you have summer-fruiting varieties or ever-bearing (fall bearing) varieties, but I know many people have both and they grow into each other sometimes. Do the best you can if you are in that situation. Remove canes that fruited last year on summer-fruiting varieties and “tip back” canes that will fruit this year by 25 percent to encourage more branching and fruiting. This means that you cut back the top part of the cane, taking off what looks like 25 percent of the height of the cane. Thin out any weak, spindly canes, removing them at ground level so you have four to six strong and healthy canes remaining per linear foot of row. Summer-bearing raspberries only fruit on second-year canes, so the ones that are left that you tipped back will fruit this year.

Overwintered ever-bearing (also called fall bearing) raspberries can either be cut down by half, and you’ll get a light harvest in spring (after they bear, cut them to the ground and you’ll get another crop from new canes later in fall), or cut them to the ground in spring for a fuller crop in September-November for some varieties. Their canes fruit on new canes (same season) so if you cut all old canes to the ground before the season starts, that is fine, unlike with summer-fruiting ones.

Visit http://learningstore.uwex.edu/ to view/print the publication “Growing Raspberries in Wisconsin” #A1610 for more information on raspberry culture.

Pruning woody plants: Red-twig dogwood and shrub willows are prone to canker diseases that infect the branches, causing discolored sunken areas in the bark. By pruning these plants on an annual basis using the thinning method, you can help keep them healthy. The thinning method is a pruning technique whereby you remove about 30 percent of the biggest, oldest stems right at ground level, then lightly prune to shape the remaining stems. The method removes older growth that is less vigorous and more susceptible to disease, and encourages younger, more vigorous growth that is more disease-resistant. It also decreases humidity by thinning out the old growth, which can help discourage foliar fungal diseases that thrive in humid environments.

Double-flowering almond and purple-leaf sandcherry are susceptible to a disease called fire blight, which is a lethal bacterial disease that often strikes fruit trees as well. It also causes cankers, but the bacteria overwinter in the cankers and ooze out in a sticky sap in spring. Be careful when pruning these shrubs as well as willows and dogwoods with cankers as any of these diseases can be transmitted on pruning shears and moved from plant to plant. For pruning diseased material, we recommend disinfecting your shears with rubbing alcohol after each cut.

See the UW-Extension fact sheet for more information on pruning deciduous shrubs http://hort.uwex.edu/articles/pruning-deciduous-shrubs and http://hort.uwex.edu/articles/fire-blight for information on pruning plants with fire blight.

Lisa Johnson, Dane County UW-Extension horticulture educator

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