Brambles, such as raspberries and blackberries, are popular with many home gardeners. They’re easy to grow and perform well in much of Iowa. However, gardeners can run into issues with pests, disease, heat, weeds, and pruning that curtail yields.
Below are frequently asked questions about common problems gardeners encounter when growing raspberries and blackberries at home.
Insect & Animal Pests
- Yellowjackets (yellow and black stinging insects on ripe fruit)
- Multicolored Asian Lady Beetle ("ladybugs" feeding on ripe fruit)
- Sap Beetles (small black beetles in fruit)
- Spotted Wing Drosophila (small white "worms" in fruit)
- Japanese Beetles (iridescent green beetles on leaves)
- Cane Borers (tip dieback, gall formation, scaring from egg laying and larvae emergence)
- Rabbits (Overwintered canes with bark stripped at base, young canes "snipped" off as they emerge)
Diseases & Disorders
- Raspberry Leaf Spot (leaves with dark green spots that age to tan or gray)
- Spur Blight on Raspberries (dark spots on canes, older leaves develop v-shaped dieback)
- Anthracnose (small purple spots on canes)
- Cane Blight (dieback of fruiting canes, dark brown or purple cankers)
- Raspberry Root and Crown Rot (stunted growth, cane dieback, wet soil)
- White Drupelet Disorder (parts of the fruit are white)
- Orange Rust on Brambles (bright orange spots on the underside of the leaves)
- Verticilium Wilt (wilting and dieback of canes starting at tips, drying of leaves)
- Powdery Mildew (white powdery substance on the leaves)
- Gray Mold (fuzzy gray mold on fruit or growing point)
- Fire Blight (cane and leaves turn black from tip down, cane tip curls over)
Environmental Factors
- Winter Damage (tip dieback, fewer flowers)
- Herbicide Injury (distorted, twisted new growth and leaves,
- Drought & Dry Conditions (wilting, dieback, dry and seedy fruit)
- Poor Pollination (small, crumbly berries)
Care Concerns
- Improper Pruning (healthy canes but no fruit production)
- Weeds (unwanted grasses and other plants growing among the canes)
- Rapid Spread (canes aggressively growing where they are not wanted)
More Information
- Growing Raspberries in the Home Garden
- Growing Blackberries in the Home Garden
- How to Prune Raspberries
- How to Prune Blackberries
Photo credits: 1:sasimoto/AdobeStock; 2: Michelle Grabowski, University of Minnesota