Problems With Raspberries

Cane Diseases

• Raspberries are vulnerable to diseases in the branches of the bushes. Cane blight is a condition that can creep in when a branch is wounded. If you suspect cane blight, you have to scrape away part of the exterior of the branch to look at the core. If you see a brown core, the plant has cane blight. Stop watering the plant from overhead and use fungicide to control infections. Cane botrytis is a fungus that attacks the plants when they can't stay dry. Sufficient air circulation will prevent this.

Disease

• Raspberries are prone to a number of fungi that infect the plants and cause serious damage. Gray mold is a serious problem for raspberries, and can infect every part of the plant. Wet and cool conditions cause the problem. The fruit itself becomes covered in a gray fuzz when gray mold is present. Verticillium affects the wood and lingers in the dirt years after the initial infection. If you notice light-colored spots on the top of the leaf, or small holes in the leaf, raspberry leaf spot is a possibility.

Insects

• A light brown beetle called the raspberry fruitworm likes to burrow inside the buds and fruit of the raspberry plant. Tarnished plant bug affects as many as 20 percent of raspberry plants but can be controlled with carbaryl. If you notice swellings in the canes of the plant, you might have raspberry cane borers living inside your plant. In that case, you need to prune canes infected by the bug once the plants have entered their dormant period.

Other Pests

• Birds and deer create as much damage in raspberries as any disease or insect. A dog will keep deer away from a garden. If that is not an option, you may need a fence. However, a fence needs to be at least 8 feet high to be effective at keeping deer away. Keep birds out of the raspberries with netting. Make sure to check the netting regularly as wind can easily dislodge it and make the plants vulnerable.