A disease known as rose rosette is beginning to spread on roses in Pennsylvania, affecting even the Knock-Out variety that is known for its toughness. The disease follows others that have afflicted popular landscaping plants, as it spreads on different types of roses through a microscopic mite from the multiflora rose plant. Roses with the disease show unusual growth on top and produce excess thorns and deformed buds that do not open, according to this article.

Related Summaries