If you are a rose person (and you know who you are), roses are not only the centerpiece of your garden but are the plant that commands most of your attention. I’m not a rose person if you can’t tell. I think my lack of interest in roses can be traced back to my experience with thorny plants as a kid… Pyracantha to be more specific.

You see it was my job to keep that plant trimmed up and dang, it seems like I was always getting poked and stabbed during the process. I couldn’t imagine why anyone would want one of these dangerous plants in their garden. This likely contributed to my desire to keep my distance from thorny plants.

But for those who love their roses, rose rosette disease is likely something you have in the back of your mind on a fairly consistent basis. So, let’s talk about little bit about rose rosette disease, especially since there is no cure for this disease.

Rose rosette disease is a virus that is spread between plants via the eriophyid mite. This is a microscopic mite which make visual detection nearly impossible. The disease is spread when one of these mites feeds on an infected plant and then somehow makes it way to a non-infected plant. They then feed on the new plant, spreading the disease.

These mites can crawl short distances, but they are typically blown from rose bush to rose bush via the wind, or carried on garden gloves, clothing, or tools. More recent research suggests that leaf blowers can also transport mites between plants. Once these mites get airborne, they can float for a fair distance to land upon a nearby rose bush.

If you are concerned your rose bush may be infected with rose rosette disease, there are a couple of good indicators you can look for. First up is, you might notice unusual growth on your rose bush. This non-standard growth is called a witches broom due to a high concentration of growth clustered in a particular area with this new growth tending to be red in color.

The second reliable indicator is an unusual abundance of thorns on the plant. Yes, roses produce thorns, but once you see a branch with a high quantity of thorns, you can be pretty sure that your rose is infected with rose rosette disease.

Even though either one of these indicators are pretty reliable (plants typically have both indicators), if you would like scientific confirmation, you can cut off one of the symptomatic shoots, wrap it in a paper towel, place it in a sealed plastic bag, and drop it by the Master Gardener office at 4116 E. 15^th Street. We can send it on to the OSU Plant Diagnostic Lab for positive identification.

One of the primary downsides to rose rosette disease is that there is no cure for the disease. With a positive diagnosis, you’ll want to dig up and remove the plant from your landscape. If you can’t quite bring yourself to do that, you can start with a pretty severe pruning, cutting off the obviously infected portions of the plant. Then watch for new growth to see if it exhibits the same symptoms. This is what we call a long shot, but if nothing else, it may get you through the grieving process before you dig up your rose bush. The reality is that once you get a positive diagnosis, you need to get rid of the plant to keep the disease from spreading to other plants.

When you do dig up the infected plant, be sure to get the entire root ball since the virus resides in the roots as well. Once you dig it up, place it in a trash bag, seal it, and deposit it in the trash.

You will also need to rake up any plant debris and dispose of this as well. Then, give the tools you used a good cleaning, finishing up with a rinse of a 10% bleach solution, or possibly a disinfecting spray. Then wash the clothes and gloves you were wearing. Remember, these are microscopic mites we are dealing with.

The official recommendation is to not replant roses in the same location for at least two months. But what are the odds you were able to remove all the roots from the soil? I would suggest you consider planting something other than a rose in that location, but maybe that’s just me.

If your infected rose was part of a cluster of rose bushes, you should begin to treat the remaining roses with a horticultural oil in hopes that you might be able to kill any infected mites that made their way to a new plant. Repeat this treatment every month, except the hot months, and keep your eyes out for the first signs of infection. If they begin to appear, you know what needs to be done.

To help minimize the spread of rose rosette disease, you can do a few things. First of all, plant your roses a distance apart that would prevent the mites from making their own way to other plants. Also, you can plant non-rose plants in between your roses, again to minimize the migration. Also, try not to use your leaf blower in the vicinity of your roses. While leaf blowers are good at cleaning up, they also are good are moving disease carrying mites around the garden.

At this point, various researchers are working to develop rose rosette resistant varieties of roses, but any solution that would come from this is likely several years away. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: Jen Olsen - OSU