At the Western Mass. Master Gardeners’ Association spring symposium in South Deerfield March 18, I was disturbed to learn from Master Gardener John Barry about a contagious, incurable and deadly disease called Rose Rosette Disease (RRD). Spoiler alert: this column was written by my alter-ego, Daisy Downer.
The disease has spread throughout the southeastern and Midwestern states and while it has yet to reach New England, it was reported in 2007 to have reached the Brooklyn, New York Botanical Garden. That’s too close for comfort.
RRD originally attacked the invasive multiflora rose, a wild species rose native to east Asia that was brought to the United States in the early 1800s. The disease is spread by the invisible eriophyid mite (Phyllocoptes fructiphilus). Multiflora roses act as the mite’s host.
Now that the multiflora rose is Public Enemy No. 1, it’s hard to believe that from the 1930s till the 1960s, the U.S. Department of Agriculture (USDA) actively promoted the planting of multiflora roses. The fragrant, attractive and super-hardy shrubs were planted along interstate highways, used for erosion control and as windbreaks and bird sanctuaries.
The USDA even paid farmers to plant multiflora roses on their properties. They were used to provide natural “fences” between pastures, since they were cheaper and more durable than post and wire fencing. One Tennessee farmer proudly claimed that “a mature fence could stop a boar hog running at full speed.”
The story gets even weirder. The first reported case of RRD was in Manitoba, Canada in 1941.When it finally became clear that multiflora roses had become invasive, taking over farmland and roadsides, plant scientists proposed using RRD to kill off multiflora roses. They assured the public that RRD would only kill multiflora roses and that other roses would not be harmed. As it turns out, they were wrong on both counts.
Multiflora roses continue to act as a host for the mites, which are airborne and can infect ornamental roses many miles away.
Rose Rosette Disease is also known as the Witches’ Broom of roses, because it often manifests itself in rampant and contorted growth patterns, often of a purplish tint. It also manifests itself in an irregular, pebbly leaf texture on otherwise healthy leaves and hyperthorny new canes, that is, canes that have an abnormal number of thorns. Different types of roses show different signs in different seasons at different stages of growth.
RRD is impossible to cure, but early detection can save an infected rose bush. The mite attacks the top of the cane and the infection spreads slowly down the cane to the roots and to other canes. Immediate removal of the cane can sometimes prevent the infection of the entire plant. If an entire bush appears infected, it must be removed, roots and all. This is important because it appears that it can spread through root-to-root grafts within beds of cultivated roses.
According to John Barry, there is little information about RRD in the Northeast. He suggested that concerned gardeners contact their local USDA office or county extension service to seek information and to spread awareness about RRD. It’s important to be vigilant about where you buy your roses, particularly if they come from sources in states where RRD is present. Eliminating multiflora roses is a helpful preventative measure.
At the risk of sounding paranoid (who, me?), the commercial rose industry has little to gain from spreading information about the potentially devastating effect of RRD. I gave up on roses years ago, but if I were considering taking another stab at rose gardening I would certainly think twice before investing a large amount of time, money and labor on a plant that’s likely to be overcome by a contagious, incurable and fatal disease. Gardening is hard enough without having to face challenges like RRD!
By all means, if you suspect that a rose is infected, remove the rose, or at least the infected cane, and report it immediately. A devoted rosarian and RRD researcher named Ann Peck has created a web book online that contains tons of information about RRD. Her website is: www.rosegeek.com.
Spring is a great time to assess woody shrubs for shape, structure and winter damage. Saturday, from 9:30 a.m. to 12:30 p.m., Berkshire Botanical Garden in Stockbridge will host an offsite workshop focused on learning pruning by doing. Ron Yaple, noted arborist and owner of Race Mountain Tree Services in Sheffield, will demonstrate how to renovate, rejuvenate and shape shrubs and small ornamental trees for structure, health and optimal growth.
Plants covered will include viburnums, lilacs, witch hazels, deciduous azaleas, sweet shrubs, crab apples and ornamental cherries.
Following the demonstration, participants will work in small groups to properly assess and prune a wide selection of plants commonly found in the home landscape.
For more information and to register, go to: berkshirebotanical.org
Mention nightshades and most people immediately think of highly poisonous plants.
While it is true that some members of the nightshade family, or Solanaceae, are toxic, several species of nightshade are among the most widely cultivated and economically important food plants in the world, including tomatoes, peppers and eggplant.
On Saturday, from 1 to 3 p.m. at the Berkshire Botanical Garden in Stockbridge, vegetable guru Ron Kujawski will discuss how to grow these delicious nightshade plants. He’ll discuss starting plants from seed, preparing beds for planting, ongoing seasonal care, pest and disease management and harvesting. Participants will go home with a variety of nightshades for planting themselves.
Ron Kujawski, Ph.D. is the former landscape and nursery specialist for UMass Cooperative Extension. He is a garden writer, educator and researcher in IPM, plant nutrition and soil science.
For more information and to register, go to: berkshirebotanical.org
The Hitchcock Center for the Environment in Amherst is offering a school vacation week program April 17 to 21 for children in kindergarten through grade 5. Children can sign up for as many days as they wish to explore the forest, splash in puddles, smell skunk cabbage and watch for songbirds and other returning migrants.
Indoor activities include art projects, playing games and visiting with live animals. Participants should be prepared for variable spring weather with warm layers and waterproof shoes. Space is limited, so sign up early. The days run from 8:30 a.m. to 3 p.m.
Members: $60 per day / Nonmembers: $70 per day
Mickey Rathbun can be reached at foxglover8@gmail.com.