Hello,

Black currant bushes thrive in medium moisture well-drained soil in full sun to part shade. Read more here: https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=257221&isprofile=0&cv

They are susceptible to attack by many diseases and insects, such as aphids. Environmental conditions, such as a late frost could also affect them. An accurate diagnosis of what is causing this problem and how to treat it can be made by MSU Extension’s Plant and Pest Diagnostic Lab. To learn how to submit a sample, go to: https://www.canr.msu.edu/pestid/

Thank you for contacting Ask Extension.