HI, I covered my roses this past winter. When I removed the cover. I found a white spider like web, like a cotton web all around the base of my roses. Is this a pest or fungus? Did it hurt my roses? What can I do to fix it? and last what can I do to prevent it next year? I live in the Minneapolis Minnesota area. Thank you.
From the brief description you gave, it sound as though your rose bush developed a fungus over winter. In most cases the fungi that develop over winter are superficial, and don't damage the rose bush, although if present for a long time could penetrate the bark and cause rot. You have several options for preventing it. Because the fungus develops in high humidity, venting the rose cover on warm days can help. You could also simply mound soil and mulch around the rose bush as a means of protection. If the problem persists, you could spray a protective fungicide on the canes before covering them.