Rose Rosette Disease: Dallas Is the Epicenter

Rose Rosette Disease called RRD and Knockout Rose Disease manifests itself with elongated and bright red branching. Knock Out roses and Drift roses are especially susceptible. RRD began appearing in about 2009 in Dallas.

Knockout Rose Disease Elongated red branches contain microscopic mites

Elongated red branches known as “Witches Brooms” contain microscopic mites.

You will see the pointed, elongated growth as shown above this is often referred to as “witch’s broom.” Your rose will have more thorns; its buds, leaves and flowers will be distorted. The rose will be become more susceptible to mildew and black spot and generally die in two to five years. Younger, smaller roses die sooner than older more established roses, but they all die. This is fatal.

RRD Knock Out rose disease contain microscopic mites

Elongated Red Branches Contain Microscopic Mites

The Rose Rosette disease is a virus carried on the wind by a wingless mite, the eriophyid mite. Mass plantings are generally all infected. There is no treatment. The rose will be infected in May though may not be symptomatic for a few months thereafter. The mites can survive a winter in the live canes and even in the roots. When you remove the foliage you remove the mites.

Because the virus is present in roots the rose really has no chance of survival. Remove the root ball of infected plants and destroy sprouts of any roots not eliminated if they develop because they will contain the virus as well.

Knock Out Rose Disease is a common name for Rose Rosette Disease. However, the cure suggested is to remove any infected plant completely. It contains the damaging mites. It has been noted that removing the damaged part of the plant often encourages the mites living within the plant to simply move lower.

The Pennsylvania nursery that introduced ‘Knockout’ roses has suggested that you prune the roses back by 2/3rds while they’re dormant in late winter to remove any overwintering mites and eggs in the bud crevices.

June Pocket Perennial Garden Canna Lillies and Day Lillies Early June Texas

June Pocket Perennial Garden: Knockout Roses, Cana Lilies, Day Lilies, Dusty Miller, Rose Rosette Disease can be seen in the rose on the left of the image with the “Witches Broom” in ruby red colors. Miscanthus Maiden Grass in the background.

Rose Rosette Disease (RRD) continues to threaten home gardens and public landscapes across the South and Midwest, and yes—some roses are more susceptible than others. The disease is spread by a tiny eriophyid mite and most often affects roses with dense growth or vigorous blooming habits.

If you’re planting new roses or maintaining existing ones, understanding which varieties carry higher risk can help you make better choices.

More Susceptible Rose Types

1. Knock Out® Series
Especially the original Radrazz and its related hybrids. Their popularity in mass plantings increases exposure, and their thick growth attracts mites.

2. Drift® Roses
Compact but densely branched, these groundcovers are often used in groups—allowing fast spread when one becomes infected.

3. Hybrid Teas
Frequent pruning and fertilization lead to tender new growth, which mites prefer. Older cultivars are particularly vulnerable.

4. Vigorous Shrub and Floribunda Roses
Heavy repeat bloomers with lots of soft stems can be easily affected, especially in unmanaged beds.

5. Rosa multiflora (wild rose)
This invasive species is extremely susceptible and often spreads the virus to cultivated roses. Remove it if found nearby.

Roses That Show Lower Susceptibility

While no rose is completely immune, some appear less prone to infection:

Rugosa hybrids – Thick canes and spaced foliage help reduce mite pressure
Some Earth-Kind® roses – Selected for resilience in Texas trials
Open-structured old garden roses like Mutabilis – Fewer dense growing points

How to Reduce Risk

Avoid overcrowded rose beds
Prune carefully and sanitize tools
Remove wild roses nearby, especially Rosa multiflora
Watch for early signs: red distorted growth, excessive thorns, witches’ broom

If you’ve had trouble with RRD in the past, consider switching to more open, resilient rose varieties—and be proactive in spacing, pruning, and observation. Prevention is still the best defense.

Top 5 Lower-Risk Roses for Texas Gardens

While no rose is fully immune to Rose Rosette Disease, these varieties have shown lower susceptibility in field trials and long-term use in Texas landscapes:

1. ‘Mutabilis’ (China Rose) Mutabilis should be in every garden. Read why.

Open, airy growth with single blooms
Long bloom season, minimal pest pressure
Less attractive to mites due to structure

2. ‘Belinda’s Dream’ (Earth-Kind®) Belinda’s Dream is a fantastic rose and has a great companion. Read more here.

Large, fragrant pink blooms
Disease-resistant and well adapted to Texas heat
Lower incidence of RRD when spaced properly

3. Rugosa Hybrids (e.g., ‘Hansa’, ‘Therese Bugnet’)

Thick canes and wrinkled leaves deter mite infestations
Cold and heat tolerant
Limited use in formal beds but excellent in naturalistic designs

4. ‘Carefree Beauty’ (Griffith Buck rose) Read about the durability of the Carefree Beauty

Tough shrub rose bred for Midwestern winters
Repeats bloom with minimal maintenance
Recognized in many public gardens for longevity

5. ‘Cecile Brunner’ (Climbing or Shrub Form) Read about the simple beauty of Cecile Brunner

Old garden rose with soft pink, button-style blooms
Vigorous but loosely structured growth
Performs well in zones 7–9 with low input

Advancements in RRD Research

1. Identification of Resistance

Researchers have identified quantitative trait loci (QTLs) associated with RRD resistance in both diploid and tetraploid rose populations. Notably, QTLs on linkage groups 5, 6, and 7 have been linked to reduced susceptibility, with some loci accounting for up to 40% of phenotypic variance in disease resistance.

2. Breeding Programs for Resistant Cultivars

Texas A&M AgriLife Research is leading initiatives to breed roses that are resistant to RRD and black spot disease. Their program integrates field evaluations, molecular markers, and genomic tools to develop sustainable rose cultivars. The goal is to produce roses that require fewer inputs and are resilient to both biotic and abiotic stresses.

This program has received substantial support from the U.S. Department of Agriculture’s (USDA) Specialty Crop Research Initiative (SCRI). For instance, in October 2022, a project titled “Developing Sustainable Rose Landscapes via Rose Rosette Disease Education, Socioeconomic Assessments, and Breeding RRD-Resistant Roses with Stable Black Spot Resistance” was awarded $4 million in USDA SCRI funding .

This initiative is led by Dr. David Byrne and Dr. Oscar Riera-Lizarazu at Texas A&M, in collaboration with researchers from multiple institutions, including the University of Minnesota, University of Tennessee, USDA-Agricultural Research Service, and others.

Regarding Department of Governmental and External Affairs (DOGE), there’s no publicly available information indicating that this department has impacted the rose breeding program. The program’s funding and progress is primarily influenced by USDA grants and collaborations with academic and industry partners.

3. Exploration of Alternative Hosts

Studies have expanded the known host range of RRD by demonstrating that the virus can infect various herbaceous plants, including tomato, pepper, cucumber, and spinach, under experimental conditions. This finding suggests potential alternative reservoirs for the virus, which could influence disease management strategies.

Fort Worth Rose Garden

Fort Worth Botanical Gardens Rose Garden with no roses

OSU notes these signs of Rose Rosette disease as well:

Elongated shoots Red or yellow leaf mottle

Leaf distortion

Excessive prickles (thorns)

Succulent, thickened stems

Witches’ broom (rosette)

Flower distortion, discoloration or blight

Branch dieback

Reduced winter hardiness Increased susceptibility to other diseases

OSU Rose Rosette Disease Fact Sheet

http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-9207/EPP-7329web2017.pdf

OSU has the best descriptive analysis and suggestion I have seen.

OSU Rose Rosette Disease Fact Sheet

Q1: What is Rose Rosette Disease (RRD)?

A: Rose Rosette Disease is a virus spread by a microscopic mite (Phyllocoptes fructiphilus) that feeds on rose stems. It causes abnormal growth and is fatal to infected plants. There is no cure, only prevention and removal.

Q2: What are the early signs that my rose has Rose Rosette Disease?

A: Key symptoms include:

Excessive thorniness (many small, sharp red thorns)
Bright red new growth that stays red and twisted
Witch’s broom: tight, distorted clusters of stems and leaves
Thickened, fleshy stems
Failure to bloom or deformed blooms

If you see multiple symptoms on the same plant, especially excessive red growth and thorn production, it’s likely RRD.

Q3: Can I test for Rose Rosette Virus?

A: Yes. Laboratory testing is available through some state agricultural labs and extension offices, but results take time. In most cases, if symptoms are clear and confirmed by local experts, immediate action is advised.