I have a dozen hybrid tea roses of about ten varieties. The garden is in northern San Diego County, California, about 5 miles from the coast. The roses were purchased from wholesale nurseries and installed seven years ago by a landscape contractor.

In 2019, I began seeing thickened, elongated stems with copious thorns. Flower production was reduced. I suspect three of the roses, all next to one another, have Rose Rosette Disease. The internet shows many images of various RRD symptoms, but I haven't seen anything like these spindly, fern-like growths that appear to be coming from the root stock.

These sprouts look like miniature stems with no leaves; they are blunt-tipped. Are they a symptom of RRD?

Thank you for any information.

Thanks,
GrowDammit

That IS unusual! I hope someone here can help.

Me, too!!!

In the mean time, thanks for observing how strange it is.

GD

It looks like another plant to me. Scotch Broom maybe? So weird if they're growing from the rose stem. Do you have any photos of leaves?

Mistletoe?

From your photos, description and location, I'm pretty sure its RRD.

"Symptoms include thickened stem growth, excessive thorns, witches' broom growth at end of stems, branch die-back, discolored and distorted leaves."

The witches broom growth is what you see coming up from the roots. I don't think there's any chance of saving your roses. If I were you, I would dig those roses out and assume all the rest have been exposes and act accordingly.

https://www.thegoodearthgarden...

Hi Daisyl.

I looked at the images on your web page, and I haven't seen anything like those symptoms -- clumps of mangled growth with closely-spaced, smallish thorns; bright red foliage and stems; die-back. I suppose it's possible my particular roses are exhibiting RRD symptoms that are not the norm, but removing all of them is a solution I need to consider carefully. I'm old and couldn't do it without help, so the work would be quite expensive.

Other questions/facts:

A member asked if I had any photos of leaves. I hard-pruned them three days ago, so no recent photos of leaves. I've uploaded a pic of half the rose bed from last summer. There's a Peach Drift next to the rock, and the three roses ahead are the ones with the strange sprouts at the roots.

I have about 18 Iceberg Roses (only one neighbor has them; most neighbors have no roses). They show no signs of disease. Are they not susceptible?

I don't have any Knockout roses.

Three years ago, I hiked a narrow trail bordered with wild roses (south County San Diego), probably multiflora (single, white flowers). If they were infected, could I have brought the mites home on my clothing?

If this is RRD, is it possible the mites were present in the nursery stock when it was purchased seven years ago? "Multiflora rose is sometimes used as rootstock for propagating other roses..."

Thanks,
GD


P.S. Just remembered: I also have two nearby Rosa banksiae (white) which show no signs of RRD.

I also do not think it is RRD. It looks to me to be more like a parasitic plant rooted on your roses.

Porkpal,

I'm going to allow those weird sprouts to continue growing, and if they do anything interesting, I'll be sure to post images.

Thanks,
GD

GrowDammit said:Hi Daisyl.

I looked at the images on your web page, and I haven't seen anything like those symptoms -- clumps of mangled growth with closely-spaced, smallish thorns; bright red foliage and stems; die-back. I suppose it's possible my particular roses are exhibiting RRD symptoms that are not the norm, but removing all of them is a solution I need to consider carefully. I'm old and couldn't do it without help, so the work would be quite expensive.

I based my thoughts on your description in the second paragraph of your first post and on the title of this thread. The antler growths on the roots do look like some types of witches' broom.

DaisyI said:
I based my thoughts on your description in the second paragraph of your first post and on the title of this thread. The antler growths on the roots do look like some types of witches' broom.

Yes, they do, and I appreciate your opinion, but I'm not ready to pull out all my roses just yet. I want to wait and see what those feathery growths look like in a few weeks.

A couple months ago, our weekly gardeners used Round Up on some ground-hugging weeds just outside the railing, 6-7 feet away from the roses. I cautioned them to be careful. I provided a cardboard shield, but they didn't use it. The roses are near the top of a small canyon, so lots of wind/updrafts. I mention this just for full disclosure, but I doubt the antler growths are related to the RU.

Thanks,
GD

If you had mentioned that before, I would have suggested Round-up drift as a possible problem, in fact, I almost did. Roses are incredibly susceptable to damage from RU drift and it looks identical to RRV.

PS: Roses often don't recover from Round-up damage but at least it isn't catching.

I think I have had several roses that actually have recovered from herbicide damage, but it took a loooong time.

UPDATE:

The strange sprouts coming from the roots of my roses have not changed since I posted on January 4th.

Yesterday, I had a "Eureka" moment. I was cleaning up under some mature Cotoneaster parneyi shrubs and discovered some of the same feathery sprouts! Then a few minutes later, I discovered more of them under a 5-year-old Camellia. The three locations are 30-40 feet from each other. The roses are in full, all-day sun. The other two locations are filtered sun (small trees nearby). All locations are well-drained soil with mulch added and are covered with layers of bark nuggets. They all get irrigated briefly every other day.

Porkpal suggested Mistletoe. I doubt that's what these are, but I'm beginning to think they are epiphytic or parasitic. If I see any flowers, I might be able to ID them.

Another weird thing is how much these sprouts look like a plant called Rhipsalis. That can't be what they are, but they sure look similar.

I'll post with any other developments.

G D

Pull one up and see where its rooted.

DaisyI said:Pull one up and see where its rooted.

Good idea! Will do that today.

Thanks,
G D

Seems to be a good news that it doesn't belong to the rose.

Yes! Very good that it isn't any kind of rose disease.

G D

I carefully dug up some of the sprouts under the Cotoneasters.

Photos:

1. It's hard to see, but I've lifted several sprouts along with a small root. The sprouts are not growing from the root or from pieces of landscape bark.

2. The roots of the weird sprouts seem to be very succulent.

3. The sprouts appear to have their own root systems; I transplanted this one into a small pot, located it near the other sprouts, and I'll post if it continues to grow.

Flowers are what we need.

G D

Cool! Keep us posted.