Raspberry Plant Problems in the Pacific Northwest

Diseases

• The most common disease problems for Pacific Northwest raspberries include:
  anthracnose, cane, blossom and spur blight, crown and cane gall, crumbly berry, cane Botrytis, Botrytis fruit rot, Phytophthora root rot, yellow rust, viruses, Verticillium wilt. Pruning the diseased canes and keeping the rows narrow with good air circulation and light helps prevent some diseases. Applying lime sulfur or Bordeaux mix fungicide, where allowed, gives the raspberry plants some protection agains anthracnose and cane blight. Water around the base, not overhead to avoid excessive moisture which can make the raspberry plants vulnerable to many of these diseases. Fungicides fight agains Phytophthora root rot. Unfortunately, there is no cure for crown and cane gall or viruses which linger in the soil long after the plants are gone. Infected plants must be uprooted and burned away from the growing area.

Pests

• Raspberry pests in the Pacific Northwest include: Spider mites, raspberry cane borers, leafrollers, thrips, fruit worms, black vine weevil, strawberry root weevil, clay-colored weevil, raspberry aphid, European earwig, stink bugs, Lygus bugs, spiders. Organic and non-organic pesticides, pruning and burning affected canes and manual removal are some effective measures that northwest gardeners can take to protect their raspberry crops. For the highest quality crop, all insects should be removed before harvest.

Worms and Caterpillars

• Pacific Northwest raspberries can also be challenged by a number of worms and caterpillars: speckled green fruitworm, raspberry looper, zebra caterpillar, Bertha armyworm, Western raspberry fruitworm, slugs, spotted cutworm and nematodes. Pesticide sprays before bloom, during bloom and just before harvest generally control a worm infestation. Check with your local nursery or cooperative extension for the particular sprays recommended for the type of worm pestering your raspberry plants.

Weeds

• Allowing weeds to grow between the rows of raspberries competes with the vines for the available water and soil nutrients and reduces air flow. This makes the raspberries more vulnerable to disease, which in turn can trigger an insect infestation of the weakened plants. Therefore, weed control is a key factor in producing a healthy raspberry crop. You can use herbicides before the blooms and fruit appear and lightly till the soil occasionally during the growing season to keep it weed free and give your raspberries the best chance to thrive.