Fungi are one of the most persistent organisms to ever infest the world of plants, particularly your garden of roses. One of the most common roses disease known as black spot is caused by the fungus, Diplocarpon Rosae. They are minute organisms that produce well-protected spores which reproduce rapidly and colonize the stems and leaves of your rose bushes. Dark spot usually tends to spread from the lowest leaves and progresses to infest in an upward fashion. But since their spores are airborne, these fungi could just as easily and quickly be transmitted by the wind or splashed by the rain to damage your rose plant all over and threaten your other rose bushes nearby.
Roses disease like black spot are surely a cause for alarm, but they can be treated and controlled through preventive measures. One mode of prevention is to know what these spots look like. It manifests itself first as tiny black spots on leaves, and these eventually turn to bigger black spots ringed by yellow. With the first signs appearing as soon as spores germinate and start to reproduce, expect the tiny black spots to evolve into the widespread blackening and yellowing of leaves within a week to 10 days if left untreated.
How do these spots as a roses disease affect your plant? It kills leaves. Leaves are responsible for food manufacture in a process known as photosynthesis, and when they are diseased and damaged, they can no longer perform this function well. Once your rose plant has become defoliated or lost its foliage by the falling of blackened and yellowed leaves, it will lose the green surface and the green photosynthetic pigment chlorophyll which helps the plant make food. Your rose plant loses its energy-giving functions and slowly withers and dies.
Since young, newly-formed leaves are very prone to black spot and other common roses disease, you have to protect them early on. Fungi favor humid weather, and as the weather gets wetter in early autumn, the conditions become more favorable for fungi to thrive. Fungi like black spot become active at an ideal temperature of 24 degrees Celsius.
Aware of this, start cleaning up your rose bushes in early autumn. Trim your roses, prune off damaged parts, and dispose through burning. Don’t ever use them as compost, because you’ll only return them to their favorite habitat which happens to be your rose garden.
What happens if you don’t start by fall? Spores can survive the winter and repeat the cycle all throughout spring and summer.
Be the early bird that gets rid of roses disease by acting in early spring. While your roses are still dormant, spray them with fungicides like fungicidal soaps and sulfur applications. They work well not only against black spot, but also on mildew and rust. Baking soda mixed with liquid soap and water is said to be another remedy. Spray these fungicides on your rose bushes to exterminate those spores. They can be washed off by rain or watering, so do this regularly in spring and continue the process until summer. Don’t let black spot overcome you roses. Overcome it through the watchful and diligent attitude which characterizes you as a real gardener.