University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Strawberry Renovation and Raspberry Pruning

June 21, 2001

Thinking about renovating that strawberry patch that seems to be declining in production? Are you ready to summer prune your purple or black raspberries? Now is an important time for addressing needs of each of these backyard fruit plantings. Results of your efforts will show in the form of higher quality fruit next season.

Strawberry plantings will need to be renovated periodically to keep them productive. Make sure to start the renovation process within 7 to 10 days after harvest has finished. The patch to be renovated should be a good planting worth maintaining; not one totally infested with weeds or serious disease problems. Immediately after harvest, mow down all the foliage with a power mower so leaves are cut about 1 inch above the crowns. Rake away all the foliage and debris and remove it from the site to avoid any disease problems.

After mowing and cleaning up the foliage, spread 10 to 15 pounds of a balanced fertilizer, such as a 10-10-10 or 12-12-12, per each 1,000 square feet of planting area. Using a cultivator or spade, narrow the row of plants to 6 to 12 inches wide. Remove any weeds. If the weather is dry, irrigate the plantings.

Purple and black raspberries require pruning three times a year. In addition to spring pruning and after harvest pruning, these types of raspberries also require summer topping to encourage development of lateral shoots off the canes. This is not needed for red or yellow raspberries, however, as they do not produce strong lateral growth.

Summer pruning consists of pinching back new canes once they have reached desired height. Pinch or cut off the upper three to four inches. Lateral branches then develop which will produce fruit. Remember purple and black raspberries produce fruit on canes that are in their second season, then the cane dies. Those spent canes need to be removed after harvest each year to keep the planting productive.

 

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