What is black spot and what is the best way to treat it?
Black spots are formations on the leaves of the plants. The tissue next to the spot turns yellow and the leaves eventually fall off. This disease occurs mostly in humid weather and is spread by spores that form on spots which are then carried from plant-to-plant by rain or sprinkling. One way to prevent black spot is to water roses early in the day, so that the leaves will be dry by nightfall. Also, remove diseased leaves and prune diseased wood before spring growth. Do not space plants too close together to avoid rapid spreading of black spot. Apply a lime-sulfur spray before spring growth begins and spray with a fungicide weekly throughout the growing season.
