Red currant plants, known for their vigour and large red berries, grow best in U.S. Department of Agriculture Plant Hardiness Map zones 3 and 4. However, fungal diseases can reduce red currants' vigour and cause damage to nearby trees.
Anthracnose, caused by the fungus Drepanopeziza ribis, is a serious disease of red currants. The disease infects newly developing leaves during wet and rainy weather in the spring months. Symptoms of infection include dark brown, irregularly shaped leaf spots and leaf drop midway through the growing season.
White Pine Blister Rust
Caused by the fungus Cronartium ribicola, white pine blister rust affects currants and the eastern white pine. The fungus uses currant plants for spore reproduction. Although white pine blister rust causes little damage to currants, it is fatal to eastern white pines in the vicinity.
You can control anthracnose infections by removing fallen dead leaves, pruning to increase air circulation and using fungicides. White pine blister rust has no cure, but planting currants 200 feet away from eastern white pine growth prevents it.