What is wrong with my red flowering currant?
I have two red flowering currant plants in my front yard. One of them looks healthy -- green in the summer and no leaves in the winter. The other blooms earlier, the leaves shrivel, and new, small, sickly leaves appear in the late summer and fall and persist. As of today, there are small green leaves on the plant, unlike the other plant, which has no leaves and healthy buds. Both plants live near one another and get regular irrigation. I have attached pictures taken June 25. Thank you for helping figure out this mystery!
Multnomah County Oregon
It's hard to tell but there are about four different disease/fungus that are common to currant https://pnwhandbooks.org/plantdisease/host-and-disease-descriptions?title=Gooseberry%20and%20Currant...
I'm inclined to think it's anthracnose or blister rust. Cultural controls include pruning to allow better air circulation and light penetration. the best time of year to prune is right after bloom. Cleaning up any leaves and fruit can help suppress re-infection next spring.
There aren't many chemical controls available to the homeowner (marked with H) but there is one that is common to the items I called out: Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate for Gardens at 1.25 fl oz/gal water. Please be sure to read all the directions prior to starting, follow them and all safety precautions stated.