University of Illinois Extension

Taking Care of Your Raspberry Patch in the Fall

Summer bearing and fall/everbearing are the two types of raspberries that are commonly grown in Illinois, said a University of Illinois Extension horticulture educator.

"Fruit is borne on two-year old canes in summer-bearing types and one-year-old canes in fall/everbearing types," said Maurice Ogutu. "If you are adding these plants to your garden, avoid over-fertilizing and supplemental watering of the raspberry patch in fall so that the canes of summer-bearing red and black raspberries can start hardening off.

"Fall-bearing raspberries can benefit from supplemental water in dry weather to maintain quality and size of the fruit."

You should prune only seriously damaged or diseased canes, he added.

"Sample at least 50 leaves on non-fruiting canes during the first three weeks of August for plant tissue analysis," Ogutu said. "Place sampled leaves in leaf analysis kits and send to the lab. You can get a list of soil testing and leaf tissue analysis labs from the local U of I Extension office.

"Apply fertilizer and lime based on plant tissue analysis results. Some sulfur and magnesium containing fertilizers such as Sul-Po-Mag or Epsom salts can be applied if needed at this time so that they can be leached to the root zones of the plants."

Ogutu recommended surveying the patch to check what types of weeds are present, and decide on what type of herbicide to use.

"If biennial weeds are present in the patch then you can control them with herbicides at this time," he noted. "Remember to follow label directions when applying herbicides."

Control fruit rot in fall-bearing raspberries by applying recommended fungicides, and harvesting fruits more frequently. Scout the patch for powdery mildew and apply recommended fungicides. If phytophthora root rot is identified in the patch, treat the affected areas by drenching with Ridomil Gold or spraying the foliage with Alliete fungicides in September or early October. Follow label directions when applying fungicides.

"Check the plants by scouting for crown borers," he said. "The adult crown borer is a moth that looks like yellow jacket. Check wilting canes if they are damaged by crown borer and check if crown borer larvae is present in the crown.

"If the roots of the wilted canes are dark red in color then they are attacked by phytophthora crown rot. Remove the infected canes. Eliminate wild raspberry and blackberry growing near the patch as they may harbor diseases and insect pests."