Rose gardening can be a very rewarding specific area of gardening. Roses, however, in addition to being good at looking beautiful, are good at developing problems. These problems can put the flower’s existence in jeopardy. That’s where rose gardening knowledge comes in to play.
While rose gardening, if you notice a rose has black spots on the leaves, the disease is called black spot. What this looks like is circular black spots with fringed edges on the leaves. Initially the spots may appear as yellowish. The leaves become yellow, starting with the lower leaves, which are infected first. The treatment for black spot is to remove infected leaves and pick up any leaves around the rose. For roses already infected, spray Manzate or Mancozeb every 3 days for 3 intervals. For future prevention, spray with Funginex every 7 – 10 days.
If the roses have a powdery mildew, the rose gardening success is in jeopardy. This is a fungal disease covering the leaves, buds, and stems with white powder spread by the wind. No one said rose gardening would be easy! The leaves curl and turn purple. The treatment is to spray Benomyl or Funginex every 7 – 10 days.
Another rose gardening injury can occur if the underside of the the leaves have blisters or orange spots. This is called rust. The blisters, which turn black in the fall, attack new growth in the spring and are able to survive the winter. The treatment is to collect and discard the infected leaves in the fall. Spray Benomyl or Funginex every 7 – 10 days.