ROSE ROSETTE AND PUBLIC GARDENS |
Due to the amplification effect (chapter 12) a large collection of roses (often a public rose garden) may be the first place RRD will be noticed in an area. Not only are there more roses gathered together than in many private gardens, but there are more people enjoying them and someone will note that something is wrong. |
The appearance of RRD in a garden neither reflects badly on the cultural practices of the people tending the garden nor on the garden's management. RRD is a result of random mite drops - random occurrences that are inevitable in some areas even some areas with low disease pressure. Allowing RRD infected plants to remain in a garden, however, does reflect on your cultural practice, and disaster will follow. |
Each garden is different. High versus low external disease pressure, amount of commitment to having a rose garden, responsiveness of the governing authority, money for replacement plants, availability of labor, availability of land, control of surrounding land, relations with neighbors, authority to change bed layouts, access to information and countless other factors influence a rose curator's ability to deal with this disease. The purpose of this chapter is to inform and help to the extent that we can, curators who find themselves in the unfortunate position of having to deal with Rose Rosette Disease. The pictures at the end are for education and also a sort of "Misery loves company" list of gardens that are (with one exception) survivors. These are simply gardens we have visited and doubtless there are hundreds of other public gardens with the disease. Some are dealing with it and some managers don't have a clue. A path to certain disaster is a lack of knowledge of the existence of RRD. (A parallel path is marked with the fiction that RRD only infects Rosa multiflora, and that Hybrid Teas and other cultivated roses are not at risk.) |
In many cases the first appearance of RRD is pronounced by local experts to be the result of accidental herbicide drift. If, instead, it is RRD, treating it as herbicide drift will give the disease plenty of time to get a foothold in the garden and spread. For the difference see the FAQ - "Are there false alarms?". A lack of access to information has been a real problem. Prior to the posting of this web site, Internet searches yielded misinformation suggesting that RRD was uniformly a good thing and that RRD seldom infected ornamental roses. State web sites were willing to repeat this assertion without looking at the data it was based upon and without an appreciation of the severe limitations of that assertion. This lulled people into a false sense of security that inevitably came back to haunt them. |
"Corporate" reaction to RRD will determine how soon the disease is controlled. Public gardens are the culmination of actions of groups of people, many of whom will have to be consulted to solve a problem. With RRD, reaction times should be minimized for best results. Even optimal reactions, may not solve the problem immediately because there are so many variables at stake. A garden may be dimished or even lost to overwhelming disease pressure. Success ultimately depends on having NO internal disease pressure and minimizing external disease pressure. |
Things not to do: |
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Don't quit and leave it to the next guy who may enter the situation clueless. If everyone does that, we will never develop protocols to deal effectively with the problem. Sadly, experience is the best teacher. With experience comes an ability to recognize RRD early. |
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Don't deny the problem exists. |
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Don't finger prune or cut off infected stems and canes to extend the bloom for an individual bush - this is certain disaster. It magnifies internal disease pressure. Doing this will wipe out an entire garden in a few years! |
Things to do: |
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Share what you learn as you learn it! The Missouri Botanic Garden has been exemplary in this. If you have the problem, others in your area do or will, too. Help them! |
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Know your surrounding area. Drive around and spot rose gardens and wild roses. Do this when 'R. multiflora' is blooming in your area and look for the patches of white. Look up into trees; multiflora climbs when it can. If you can't remember them, plot multiflora locations on a map for future reference. You may need to inspect them when they are not in bloom. Keep an eye on them and get to know the local rose growers. Remove wild roses if possible or if it is necessary depending on your disease pressure. When multiflora sickens, the sick colors will catch your attention, if you know where to look. |
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Increase space between beds and use smaller beds with fewer plants per bed. Denser rose plantings greatly facilitates the spread of RRD. Mass plantings in an area of high disease pressure will be expensive to maintain. How much money, labor, and comittment is available to keep the mass plantings? That will vary with different gardens. |
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If there are unmaintained mass plantings of "carefree" roses in public areas that are upwind of your roses, try to watch them for signs of RRD. |
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If you have the space, set up a quarantine area for suspect plants well away from the other roses. This may save money over time, as well as provide replacement roses. Also, if you teach yourself how to graft, you can test suspect plants. |
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Keep records of how many plants you lose to RRD. See if there are patterns in the gardens that relate to wind patterns. If you have a digital camera, take pictures, too. I scan blooms, buds, stems and leaves that show symptoms that I haven't seen before. In my first two years of looking at RRD, I didn't notice the aberrant growth on stipules and sepals; I'm glad that I have some photo records from those years to show symptoms that I didn't notice at the time. |
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Something we don't know with any precision is the time of the year at which gardens in a certain geographic area are most likely to become infected. Large rose gardens could be an excellent source of information to determine the months at which symptoms are most likely to show. |
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The personnel at Iowa State reported that no one in Iowa has reported RRD in their rose gardens recently. Perhaps. I know of one rose grower fighting RRD who lives just south of the Iowa-Missouri state line. Doubtless her roses would be totally healthy if she were to move them to Iowa instead of seeing them begin to die of RRD in Missouri. (I almost should apologize for this snide comment, but I really don't think man-made boundaries affect or limit the spread of RRD, and I consider that the Iowa State comments beg the problems currently suffered by states and nations downwind of Iowa.) |
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Since that was written I have had reports of RRD in the well known and loved Reiman Rose Garden at Iowa State as well as in private gardens in adjacent counties. The northward spread and recognition of the disease was inevitable. |
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I do know a lot of rose growers and I talk to some of them. Talking about sick roses is seldom a priority especially with some age groups. Some seem to think that all roses except their own are perfect and they are very hesitant to ask for help when something they don't understand happens. Further, attempts to report this to extension agents leads to varying success. If the reporter is in an urban county, where there's an extension agent who deals with home landscaping, there may be some interest. In other counties, extension agents will tell the anguished rose grower that RRD is a good thing in that it will destroy Rosa multiflora. The anguished rose grower is seldom amused. |
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Once a gardener has dealt with RRD, there is potential to do good. Applying the golden rule to rose growing means helping your neighbors deal with this disease. A side effect will be to make your rose growing environment healthier. There will, doubtless, be symptoms I haven't seen yet or that I didn't recognize. There may be roses that are resistant or that can live with the disease. There may also be hypersensitive roses; their identifications need to be known. Please share what you learn. |
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Add to the body of knowledge. You are in a position to learn more about RRD. Notice which plants don't seem to get it (if any). This is where the grafting comes in. If the plant has RRD and simply doesn't show symptoms, a graft onto a seedling multiflora followed by subsequent RRD in the seedling will tell you that the asymptomatic plant is just that. Such a plant would be bad news for a garden as a continued source if infection. There is no list of such plants. That knowledge simply does not exist. |
Second Guessing: As a rose grower in a private garden, I'm lucky - nobody is looking over my shoulder except my husband and he shares this passion. Somebody has to have the final say on the matter of pulling out a plant. We have established a threshold of three separate symptoms as our personal standard to prevent misdiagnosis. If the plant next to the suspect plant had RRD, we count that as one symptom, so two more will condemn it. We find it works well for us, but acknowledge that it is an arbitrary standard. Establish and use what ever standard works for you. The decision to say that a plant has RRD, at the earliest possible time, is a judgment call. I have asked total strangers to tell me if certain strange growth is something they have seen on their examples of certain cultivars ('Seven Sisters' and 'Rosa foetida bicolor'). Many rose growers are good people and I've had help from as far away as England and Washington State and Australia. |
Digging a rose out of the ground and putting it into an isolation area is an alternative to immediate destruction. You might choose to call it quarantine, but whatever the name, the roses should be doused with a systemic miticide to kill any mites that might leave that rose. This allows you to remove suspect plants and stop further spread from within your garden. With time, you can see if you were right or wrong, so your future determinations will be more accurate and you will be more comfortable with them. With experience you can spot a growth problem across a garden. Something might "just look wrong". Then you look closely for specific symptoms by comparing potentially sick parts with healthy parts of the plant. |
Training: In our garden we both look at a plant to make a determination. Not only are two heads better than one, but if we both see it, one of us will often see something the other did not. That makes it a learning experience and gives greater confidence in the diagnosis. If someone spots a potential problem and tags a plant for the curator's attention, have your entire staff look at it so they will learn what to watch for in the future. There are also lots of pictures on this site they can enlarge (by clicking on them) and examine. |
Pesticides: There are no pesticides that are guaranteed to kill all the mites the first instant that they land on a rose. The aquisition time of RRD could be as little as fifteen minutes. Worse yet, with a "bug" that reaches adulthood in only seven days, the continued use of one miticide is basically a breeding program for a better mite. |
Avoidance: See Chapter 12. |
Below is a list of public gardens where RRD has destroyed roses. Many of these are based on our own observations. Others have been reported by knowledgeable rosarians. |
The late Lincoln Memorial University Rose Garden, Harrogate Tennessee |
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Atlanta Botanic Garden, Atlanta Georgia |
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Ben Lomond House and Garden, Manassas, Virginia |
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Lanier House, Madison IN |
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Fernbank Science Center Rose Garden, Atlanta Georgia |
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Cheekwood Botanical Garden, Nashville Tennessee |
Bob Whitaker reported spring 2002 that 'New Dawn' over an arbor was infected with RRD. |
Rose Garden to honor Ted and Mary Alice Mills,Veterans' Park, Soddy-Daisy Tennessee |
Fall 2001 Dr. Casandra Cansler, curator, saw a problem and we confirmed RRD on several red HTs in the garden. |
Kentucky Arboreteum, Lexington Kentucky |
Dr. Tim Phillips (who works with the rose garden although his primary assignment is turf grass) reported a list of RRD infected roses that added a number of classes to the list of roses that can contract RRD. He has seen symptoms on spinosissimas that are more pronounced than those reported in Viehmeyer. |
Thornrose Cemetery, Staunton Virginia |
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Red Cross Headquarters Rose Garden, Asheville North Carolina |
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Phipps Conservatory and Garden, Pittsburgh Pennsylvania |
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At the Phipps Conservatory a mass planting of 'White Simplicity' roses had a single plant with RRD symptoms.
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Helen Cuddy Memorial Rose Garden, Shawnee, Kansas |
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Capaha Rose Garden Cape Girardeau Missouri |
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At Capaha, a single bush of the Hybrid Tea, 'Mikado', was sick with RRD in October 2002. |
Missouri Botanical Garden, St. Louis Missouri |
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Gage Park, Hamilton Ontario Canada |
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Royal Botanical Garden Burlington Ontario Canada |
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