The first infested case in the United States was confirmed in the Rocky Mountains in the 1940s. It was later discovered that the virus infects primarily the multiflora rose, which was brought to North America from Japan with the disease present, according to researchers at Oklahoma State University. As well as being a vector for disease, the multiflora rose is widely considered to be invasive.

Rose rosette disease has spread to rose populations across the continent. The disease is a serious issue in the rose growing industry. In fact, faculty affiliated with the Virginia Tech Cooperative Extension recently declared it one of the most concerning diseases, with most cultivars vulnerable to it. There is no known treatment.

Rose rosette disease (Emaravirus sp.) is spread primarily by two eriophyid mite species, but it can also be spread through grafting. The mites are invisible to the human eye and move from rose to rose mainly by the wind. Once they land on a host, they infect the rose while feeding.

It can take up to four weeks for symptoms to show, usually around the middle of the growing season.

Many of the symptoms are odd. The most common is masses of new growth, predominantly red or sometimes yellow. Rose rosette will also cause unusually long shoots, soft thorns that are more numerous, distorted foliage, swollen stems and dense clusters of congested foliage. Many of these symptoms are mistaken for normal new growth or herbicide damage.

Infected roses will decline until they eventually die. Miticides may be sprayed to slow the outbreak, but most treatments are of limited help because of the size of the mites.

Infected roses should be removed entirely, bagged and disposed of in the trash. This means all parts of the plant — from blossoms to roots and everything in between.

Without a host plant, the mites will die. Since they need the wind to spread, avoid using leaf blowers around roses. Giving roses proper spacing to avoid crowding will help control the mites and mitigate the disease.

When replacing an infected rose, wait at least one or two months, and watch for any root suckers that might pop up. Remove any multiflora rose near other roses, since it is the primary host for the mites.

Only a handful of rose species are believed to be resistant to the disease. Rose breeders are working to create more.

Roses are beautiful and have been a staple in gardening and landscaping for centuries. Despite the threat that rose rosette disease poses, roses can and should continue to be garden mainstays with proper prevention and control.

Wild Green Yonder is a monthly feature from the staff of the Norfolk Botanical Garden, where Tensaie Fesshaye is a rosarian. Send gardening questions to askaplantquestion@nbgs.org.

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Correction. A correction was made on June 11, 2024. Because of incorrect information provided to The Virginian-Pilot and Daily Press, an earlier version of this article carried an incorrect byline. The writer was Tensaie Fesshaye, a rosarian at the garden, not horticulturist Jake Litchfield. 

When thinking of plants and medicine, usually herbal remedies are what come to mind. Botanical remedies have been used throughout human history by civilizations around the world. Today these natural cures are still widely practiced and have become a modern industry. Of the many plants used for medical research and treatments, certain plants have become staples in the pharmaceutical industry. These plants are valued for their naturally occurring chemical compounds used in the production of modern pharmaceutical drugs.

The Pacific yew (Taxus brevifolia) is a coniferous tree native to the Pacific coast of North America. This tree became an important part of cancer treatment when it was discovered that paclitaxel, a compound in the bark, could stop cell growth and division. This compound is the main ingredient of Taxol, a staple chemotherapeutic drug. The drug is now used in the treatment of cancers of the head, neck, breast, lung, pancreas and esophagus.

The trees in the genus Cinchona are the source of an important ingredient used to treat malaria. Native to South America, this tree’s bark contains many alkaloids, one of which is quinine. Classified as an antimalarial, quinine is used to target the infectious organisms responsible for malaria. Quinine is also used to treat babesiosis infections spread by ticks.

Madagascar periwinkle (Catharanthus roseus), a common garden annual, is another plant used in the treatment of cancers. The leaves of this plant contain two alkaloids, vinblastine and vincristine, which are used in chemotherapy drugs. Both chemicals operate by slowing or stopping cell growth and are used to treat Hodgkin’s disease and non-Hodgkin’s lymphoma. Vinblastine is specifically used to treat testicular cancer, breast cancer and gestational tumors as a secondary option. Vincristine is used to treat kidney cancer, nerve cell cancers and muscle cancers in children.

Chili pepper plants (Capsicum annum) are grown in warm climates around the world. Native to Central and South America, the fruits of this plant are commonly used for food, spices and in ornamental gardens. Along with these uses, capsicum, a natural chemical found in the fruit, is used to produce painkillers. Capsicum is primarily used in ointments and creams that treat rheumatoid arthritis, osteoarthritis and various other painful medical conditions.

There are hundreds of species of yams (Dioscorea) found in the world. While commonly grown as food, some species are grown for the compound diosgenin. Diosgenin is used in the laboratory production of estrogens and DHEA. Estrogens and DHEA are used to treat various medical conditions that occur in women during menopause. Estrogens are also used to relieve the symptoms of certain breast and prostate cancers.

From common sicknesses to deadly diseases, plants have always been a key part of medicinal practices. As herbal medicines become more popular and the industry grows, it is important to know the differences between herbal remedies and pharmaceuticals. While herbal remedies can be taken directly or easily prepared at home, pharmaceutical plants are harvested for chemicals used in the laboratory production of prescription medications. Though pharmaceutical plants are not as well-known as herbals, both play key roles in promoting health and easing suffering. This is precisely why it is so important for our species to leave plenty of room in this world for other species. After all, we never know where the next miracle drug might come from.