Black Spot On Rose Canes

You have Black spot on your rose canes. It is a fungal disease that affects only roses. It can winter over on infected canes such as yours. Sanitation is the key to keeping it in check. Cut the infected canes back as much as possible and discard in the garbage. In between cuts, sterilize your pruners with either a mixture of 1 part bleach to 9 parts water or wipe the pruners down with rubbing alcohol. Clean up any dead leaves that may be present because they can harbor the fungus . Put down a light layer of mulch such as a shredded hardwood mulch. Do not use rocks of any kind because when it rains, the water will splash up underneath the leaves and spreads the disease. You can apply fungicides as a preventative treatment and may have to apply during the growing season as well. Excellent air circulation is important too so having it in a sunny open spot is ideal. I’ve included a link for more information on Black spot on roses. https://extension.umass.edu/landscape/fact-sheets/black-spot-rose