Looking online, only sulphur and chlorothalonil were recommended and those are sprays. I can get Bonide spray which is a mix of sulphur and pyrethrin. Not great for beneficial insects, but I would only be treating a couple of plants in a very small area . . . the only systemic I see for sale is Propiconazole, which seems pretty serious. I would only use such a strong toxin if I thought it has a chance of working on my couple of roses. But I'm not going to pour a toxin into the soil if it is a lost cause.

Any chance you could get a better picture of the rose itself? I'm having a hard time zeroing in on it

I guess that would help wouldn't it! I can take some photos of the bad parts too, but I'm pretty sure it's some type of stem canker, even today I noticed the fruiting bodies on the stems . . .

Also if north creek farms is still run as a nursery they do you have it listed for sale as well as Hortico in Canada.

Rugosas often do not react well to chemical sprays.

http://www.easyrosegardening.com/rugosa-rose.html

Yes, these rugosas are supposed to be hardy, and ours was, but it's just not a happy spot I guess. The stones were a problem but I cleared out as much as I could around the base. Huge Japanese beetle problem which I am trying to get under control with organic methods (milky spore and beneficial nematodes) and then I had to figure out how to water it due to us not having an outdoor hose spigot, but now we have a rain barrel. I thought if I pruned out the diseased canes the rose would outgrow the fungus, but so far that doesn't seem to be the case . . . I removed the old canes from my property after pruning to avoid spreading in my yard. I'm not very familiar with fungicide treatments and roses. Have not had much of a problem with it prior to this.

I also think that using cedar bark mulch and leaf mulch was a mistake for the roses., and my phlox get all mildewy too. Wondering what to use for an alternative. I'm using store bought bagged compost for the little flower garden in front of the rose area and trying to keep all rotting leaves away. Trying to get my own compost going but my production is low right now. I keep the bark mulch away from right around the roses but it creeps . . .

I tried neem oil for both fungus and Japanese beetle. Did not do much for either. Luckily since I got the grubs under control, my beetle problems are much much less.

I'm wondering if this is powdery mildew or downy mildew. Powdery mildew is often found In areas of Low rain So maybe that is an issue if your rose is not being watered enough. Downey mildew needs fungicide. If it's powdery, you could also try a dilute milk spray. Skim milk is fine. Are you trying to compost your leaves? I add manure to mine and they go right down. It makes a wonderful leaf mold compost. I have mainly oak.

Nothing on the leaves. They get yellow eventually and die, but no spots or mildew on them. Here are some photos. Tried to get fruiting body but its blurry. The rose looks fine now, but you can see where the new growth died off last year. The real problem appears at the base, IMHO. FWIW, it usually blooms a second time in fall and didn't do much last year.

Do you know your soil pH? Rugosas have a decided preference for acidic soil. If you know your pH is high, or even if you don't know, I'd start with a soil acidifier before resorting to fungicides. If nothing else, sulfur is relatively harmless, and the effect will go away in time.

Well, last time I checked it was fairly neutral. I was thinking that the soil might be a little "blah" due to it not having a lot of organic content. We have gravely sandy soil here with limestone bedrock, and when you mess with the topsoil, not much good stuff left, plus all those rocks can't be leaching anything good into the soil . . . I'm thinking maybe scoop out all the tough carbon bark mulch that is left, and get a bag of peaty compost mix from the garden store and top it with some spruce needle mulch from under my Norway spruce. At the very least, it would help with the moisture retention . . .or are spruce needles allopathic. Just my luck they would be . . .

Most physicians in the Northeast are allopathic.

May your brain always be fresh and clear Rifis. Allelopathic.

Remember you are talking about a plant that thinks Maine sand is among the greatest soils on earth. However, neutral soil is not to its liking.

I think your Buffalo Gal is grafted onto a root stock. Grafting was done more so 20 years ago, and that is how she was marketed then. The bush was forced to restrict its new growth to the bud union area and not grow out in a 'colony,' type bush, with new growth emerging below ground and spaced nicely around the original bush as hybrid/species Rugosas want to grow.

The top graft has gotten so woody and congested with old, dead bud union growth shown in your photos, congesting further over the years, that new growth is getting less easy to break forth. The dead old growth there is not disease, but perfectly normal, but forming a restricted zone where new basal, bud union shoots can only emerge with much difficulty from a congested bud union area.

If your bush had been planted with its bud union 4" below soil level, the top graft Rugosa would have grown its own roots, and grown normally, colony like, which is typical for Rugosas and most of their hybrids.

Rugosas are notoriously difficult to root from cuttings, very fussy and picky, and rot in a heart beat if you just look at them funny! 😁

Why not replace your Buffalo Gal with an own root only, Schneekoppe, aka. Snow Pavement, ON ITS OWN ROOTS, and watch it thrive. Schneekoppe Is my favorite Hybrid Rugosa, and I tested about 30 different varieties of HR's many years ago, so I have had a lot of experience with them.

Your current Buffalo Gal is not diseased in any way, shape, or form, just struggling to grow as an older grafted bush instead of NATURALLY on its own roots.

Rugosas are never sprayed with ANYTHING, even liquid foliar feed. As tough as they are, their foliage will be severely damaged by any chemicals applied, except water! Anyway, your bush's growth looks very healthy to me, other than it struggling to grow husky, restricted by growing from a graft.

Moses

BTW, I do not think your soil is an issue. Rugosas and their hybrids are pretty adaptable. If you can grow peonies, you can grow Rugosas/Hybrid Rugosas as well.

Moses

Thank you so much Moses! Makes total sense!! It looked like some type of issue with a graft but I'm not much familiar with that kind of thing . . . also explains why it did great for a while but is now struggling. I kept thinking, "If I could just get some fresh growth to spring up from the roots . . . " I landscape mostly with natives, not much of a fan of grafts although I know they give us some of the beautiful wonders of the modern horticultural world.

Also thanks for the encouragement on the rooting. I had a feeling I was out of my league but I gave it a try anyway, I had the cuttings from doing a hard prune last year.

N. Michigan has soil like Maine. S. Michigan has usually great soil, although my area is a moraine and has areas of glacial debris that can lead to some pretty funky microhabitats. The lot I inherited from my folks theoretically should have good soil as it was along a creek and covered by a hardwood forest. But it has had a lot of disturbance and poor planning and management over the years. Slowly trying to reclaim it but its a large lot with many issues. For example, rock/gravel as "mulch." Don't get me started on that!!

I've had some other experiences trying to get rugosas to grow in another semi-wild situation and they just didn't seem to thrive, even right next to others that were thriving wonderfully. I didn't realize grafting was a thing with rugosas so now I'm wondering if the difference between the ones that were thriving and the ones that were dying (similar to mine) was the depth of planting. My experience with grafting is with trees where the graft is near the root collar and I always thought not to bury the graft it would create a path for disease Also wondering of a good source for me to either order or buy an "own root" rugosa. I've seen some gorgeous rugosas, just huge healthy bushes, it would be nice to have one on my property in that spot. Like maybe if I plant for it now I can implement it next year . . . I'm in S. Michigan along the OH IN border.

I recommend planting a grafted rose on a slant with both the roots and the area above the graft in the correct area to form roots. Then Nature decides which root system is better for that plant in that soil.

This not my original idea, it has been around since the late 30s or early 40s.

One example:

http://www.coldclimategardening.com/2011/03/02/plant-grafted-roses-the-easy-way/

I don't know how many own-root rugosas I've tried to grow, and every single one looks like yours. We have good soil, if you can ignore the rocks, so this has been orchard country for a few hundred years. However, it was lakebottom a few thousand years ago, and very limy. My soil consistently tests at 7.2. Over the years I've learned that when things don't do as well as expected, to start digging into their pH preferences. In almost every case, I've hit the magic words 'prefers acidic soil'.

You may be right Mad. In fact, I suspect that's why so many things don't thrive on my property, they need mildly acidic soils (the kind you would get with natural decomposition of organic matter) and mine are closer to 7 pH than 6.5 since the natural decomposition cycle was destroyed by developing the property . . . most problems begin with the soil don't they!

On a totally unrelated to roses tangent, wondering what kind of mulch could help right this. I am working on mass mulching all the leaves from the trees on the property, but also to create woodsy islands I am about to order some hardwood bark fines. Wondering if there is a better option for a mass situation. I am also debating since there is free mass compost from the municipal facility but I am so worried I will get some kind of game ending toxin since there is no oversight of what gets dumped. Almost everyone dumps appropriate things, but it only takes one bad apple. Too bad I don't live near a mushroom farm!!

Is there any way you could propagate it by layering? Then you would end up with an own root rose.

Rugosas work here. I think I have ph 7. I think you need a fresh start with own root rugosas from High Country roses or Corn Hill and improve your soil in an acidic direction.

Wasagaming is the pink.

Suzy Verrier died and last I checked North Creek Farms was no longer selling roses. This plant was from Suzy.

I had read that sad news which is why I was wondering about north creek farms. It is listed still when i search.

Soil fertility and soil pH are two different, not necessarily related, things. There exist quite fertile soils that happen to have fairly high pHs.

Sorry to hear about Suzy. We visited North Creek about 20 years ago. It was late enough in the summer that the rose selection was practically non-existant, but I still regret not purchasing one of Currier McEwen's Siberian iris seed packets.