Unless you happened to do something like spraying Wilt-Pruf on them during the heat of the summer, I've no idea what they might be suffering from. And that's no surprise anyway; I don't know much beyond what I read in terms of bugs and diseases.

In a followup post, you might mention the sprays and fertilizers you've been using, and what the temps were, etc. (But with that many roses, it seems extremely unlikely that you've suddenly failed to follow label directions after all this time with roses. I'm just thinking about sprays generally here because I lost a rose to Wilt-Pruf spray in the summer heat, and almost lost another. The damage was evident within half a day's time and it was severe.) Also consider posting the names of sprays of any kind that you might be using nearby on the lawn or the neighbor's plants.

You haven't done any extreme amount of pruning on those that are suffering, have you? The roses aren't all one kind, are they? Not all rugosas? With plenty of sun, I don't suppose you have hickory or nut tree roots for competition. Any ideas about your soil's PH? Watering in tiny amounts regularly in a dry climate can produce too much alkalinity and that might also magnify the problem if a little too much fertilizer was applied at one time. Once every few weeks if you water really deeply, that ought to flush the soil some and help, if PH is actually a problem. How quickly to the leaves die? Do you see some gradual yellowing first? (Just fishing in the dark. But I'm just sorry and wish I could help.) The leaves on my summer Wilt-Pruf deadened plant dried up and started becoming chrispy within one day. No kidding. The canes showed damage within one day too, and continued to get worse until we had no hope of the rose recovering. The other rose that almost died eventually did recover and other roses showed no damage at all, but I'll never use Wilt-Pruf in the summer heat again.

"Ridges" is a little too vague a symptom to try to look it up in any of my rose books. If by "ridges" you happen to mean some splitting apart of the outer layer, splitting that goes on down the stem, then sawflies/rose slugs did that here. It might be a bit late in the year for most sawfly varieties to be active now, though, so that seems unlikely. Maybe if you could post some pictures, someone will recognize something? Try to get pictures of your roses in various stages of coming down with whatever it is.

Good luck with finding out what it is and what you can do about it!

Best wishes,
Mary

Contact your county ag extension agent. Because there are some major rose growing areas in Arizona now, you should be able to get answers from them.

Ask them if this is the time of the year when Downey Mildew hits roses in your area. Also ask if there is a verticillium wilt problem. Ask if the fungus that has affected California oaks could be a problem coming in with mulch to your garden.

When the leaves fall, be sure to bag some for the plant pathologists to check for sporangia.

I haven't sprayed them with anything. The only thing that I have applied to them is Miracle Gro for Roses and I did that as per the instructions. Usually I use organic everything but I injured my hand and I had this from before I went organic and it was easier to use.
There was actually some roses that died before I fertilized and I had already cut/dug them out.
There's no lawn any where close to it. I have no lawn and most of my neighbors don't either. We live on non-irrigated acreages.
The only trees in the area are acacias.
My watering is done with bubbler type emitters and in the summer they get 40 minutes at 10 gph every other night. As it cools of course I cut that back on days and actually add to the time length. They also get rinsed off every so often.
They have been hybrid teas, floribundas and a couple of David Austins.
No gradual yellowing of leaves, they just shriveled up and died within a couple of days.
No splitting, the ridges are the appearance of the canes as they desiccate and then turn black/brown.
I had hoped to talk to someone from the rose society at a plant sale/demo at our county extension offices this past Saturday but the Rose society wasn't there as advertised. I'll give them a call :)

Hey, let us know what you find out. There are a lot of master gardeners that post on these forums. Making posting a picture would help them analize your problem. Wondering if it has something to do with your soil? My best friend was showing me some snapdragons last week that has some type of fungus or wilt. It happened to some plants that were planted in that area last year she said. She was wondering if it was either of the above but to me it looked wet in the area but dry where the snapdragons were(by her eye)but not to mine. I didn't see any mulch around the plants. They usually use pine straw for all their plants. There was none..maybe they were seeing what would happen to the plants there this year before they wasted the pine straw. I know we had a wet 2009 Spring and I had similar problem with verbena and once the hot temps came in July, they turned around and did beautifully. Maybe snapdragons don't like wet feet either.

Carolinamary, that was a great logic list, working through this problem.

To that I will add, have you checked the emitters on the affected plants? I've had drippers go out in my smaller garden in the heat and you can see the results very quickly. In my case, we have extremely hard water and they can get clogged, in fact I've even had 1/4" tees block.

On a side note, are these very large plants? I assume you have sandy soil? As fellow 'dripper' (HA!) just wondering how you came to the ~6gal of water every other day. OH, one more thing, what have your temps been lately?

Two other questions:

1. What type of mulch & how deep is it?
2. How often did you feed your roses with the Miracle Gro?

I did check the emitters and they are all ok. Usually I check these every month to make sure they are running ok because we have hard water too and I have the same problem.
These are plants that were around 4 feet tall and about as wide.
The soil is a bit sandy and I checked drainage on the planting holes before I planted to make sure they drained properly.
I read that roses need about 4 gallons+ every other day here in the summer when temps are in the 100's. Since these are good sized plants and since the soil is a bit sandy, I wanted to make sure they were getting enough. I tested the watering by watching the plants through the years. This seems to be what works for my plants.
It has cooled off here finally but we have had a spike here and there so it has been in the 80's and 90's. Just a couple of weeks or so ago it was in the 100's.
Since it has cooled off, I have stretched my interval out to once every 3 and now to 4 days.
I have got to say that I love my drip system! Before I installed it, I used to spend about 2 to 3 hours a day watering my over 200 roses. It was very inefficient watering by hand. It's great being a "dripper" :)

There's no mulch on there right now. I am doing fall clean up. Usually, I mulch with compost and put it on about 2 or 3 inches deep.

I have only fed them with Miracle Gro this one time in the past couple of years or more and I did the dissolve in a bucket of water and pour at the base of the plant method instead of the foliar feeding method. I believe it was one tablespoon in a gallon of water but I used more water.

We posted a little about this on the AZ Gardening forum.

Ridges on canes are indicative of dry soil and/or drying winds. You may need to check those bubblers and flush your irrigation. When you planted those roses 4 years ago, you planned water for new plantings. Four years later, those plants are substantially larger and require more water. On average they should receive 5 gallons per plant, 3 times per week during the summer. More for larger, less for smaller. Hard water and sunlight are hard on any drip system.

Disease and pests are almost non-existent during our summer months except for spider mites. Hosing off the bushes 2-3 times a week with good water pressure usually keeps their damage at a minimum. We don't get downy mildew in the low desert and powdery mildew is a spring disease. Spraying with any type of oil-based product or applying fast-acting fertilizers while daytime temps average above 90F will have an immediate and detrimental impact on roses. If you fed trees, grass, bedding plants or sprayed for any weeds or pests within several feet of your roses, those bushes will show environmental problems faster than others.

Reflection of summer sunlight off a swimming pool, especially if the bushes are mulched with gravel, will give an appearance of dryness.

There are five local rose societies in the Phoenix area and I don't know of any that were scheduled at the Desert Botanical Garden or the Extension Office. I helped at the Ext Office a couple Saturdays in October and they never mentioned needing a representative. Rose society meetings are free and you would be welcomed at any of them. As President of the Phoenix Rose Society, I would love to invite you to our November 16th meeting, 7:30pm, at the Valley Garden Center, 1809 N 15th Ave, Phx (between Thomas and McDowell, south end of Encanto Park). The other rose societies are:

Glendale - 1st Thursday of the month (Nov 4), 7pm at the Glendale Woman's Club, 7032 North 56th Avenue.

West Valley - 2nd Tues of the month (Nov 9), 7pm at LandscapeMart, 8028 W Thunderbird, Peoria

Mesa/East Valley - 2nd Thurs of the month (Nov 11), 7pm at Paul Elsner Library, Mesa Community College, Dobson & Southern

Scottsdale - 2nd Wed of the month (Nov 10), 7:30pm at the Eldorado Park Community Center, 2311 N Miller Rd.

Most everyone I've talked to has lost several roses this year. Some roses just can't tolerate sustained heat, dry air and high alkaline clay year after year. If you need more information on your soil, a highly recommended local soil lab is Inter Ag Services (IAS Labs), 602-273-7248. It isn't free but they do run comprehensive soil and tissue analysis for several rosarians.

The "ridges" on the canes seem to me to indicate lack of moisture. I get the same look on canes where the root system has been damaged resulting in no water getting to them. On those dead bushes you removed, did you check to see if there were sufficient roots?
A link to a list of Arizona rose societies follows along with contact information for each one. Those societies that are highlighted (all but one) have websites and you can link by clicking on the highlighted name.

Here is a link that might be useful: Arizona rose societies

If the problem is drought related you may want to consider adding mycorrhizal fungi.

"drought conditions can be improved by using mycorrhizal fungi inoculants to improve moisture retention of sandy dry soil and enable a partnership between plant roots and fungi that has allowed plants to survive droughts."

Above quote from link below.

Here is a link that might be useful: link for above

Did the symptoms start shortly after the removal of the mulch? If your mulch is normally a nice, dark color but underneath it you have light-colored sandy soil, I'm wondering if it's sunburn due to increased reflection.

I'm guessing you don't have very many overcast days where you are? :) I know that here, in my much milder zone 5, even temps of 70 degrees will fry my roses if I don't have the entire bed protected with mulch. My soil gets a hard, crusty top & turns light gray. Combine that with a light-colored residential siding & I might as well be planting roses in front of a mirror.

Moroseaz, I actually didn't have the drip on these plants when they were small and since I added the system, I have been diligent about checking the water that has been getting to the roses. It had been about 6 gallons every other night and I have gone to 6 gallons every three and now 4 days the past couple of weeks because the temps have dropped.
I actually keep a 5 gallon bucket of drip parts on my patio that I use regularly to keep things running right.
Quite a few of my plants did have powdery mildew this past Spring before the nights warmed up. That has been gone for a long time though.
I have lots of lacewings, spiders and preying mantis and don't have any problems right now with pests.
I don't spray with anything that is not organic and haven't actually sprayed or even used anything at all (other than the Miracle Gro) for months.
The Mesa group is closest to me and I actually used to belong to the group for years. Looks like I need to sign up again.
Karl, I thought the same thing about the lack of moisture. Let me ask you this, is there a nutritional deficiency or disease or whatever that would cause a plant to not intake water?
When I dug up the dead ones, they had beautiful, big roots. I was shocked that they were so healthy looking with no damage because I thought that it could have been squirrels.
Thank you for the info.

Have Chili Thrips been reported in Arizona yet?

They are not confined to roses, but have lots of potential host plants. There's good info from Florida about what their symptoms look like on roses.

Too many salts in the soil can interfere with water uptake but if they get 6 gallons every other or third day, there should be enough drainage to keep any salts to a minimum. Nematodes in Florida cause a loss of water uptake by plugging the system,(the reason they use Fortuniana root stock), but I've not heard of this problem in Arizona. Transpiration of water from the leaves is what pulls water through the system. As it's lost through the leaves, it's replaced and pulled up from the ground. If the leaves dried up, this could have shut off the bush's water pump causing the canes to dry out and get all wrinkled as a result. Best to contact a local expert as all my suggestions are guesses.

It does seem that with all the suggestions of what might be the problem, something sure does appear to be a fox in the chicken house.

From what you say four of the plants ALL came up with the same problem...at the same time?...or gradually.
I cant pass judgment on how much water they are receiving...desert conditions I suppose warrant giving lots of water....but..to a plant that does not like to have wet feet. Even in such onditions of Arizona, there can be too much given a rose IF say, in the four years conditions have changed. In such time, possibly the drainage of the plants has changed, perhaps dramatically, to cause the roots to be, either not being given sufficient, or they are harboring too much...being given water every 2nd night.

There is always the possibility that there is a disease that is rampant in the area on roses....or the particular rose plants have, in them, a bredded disease that only comes to light after a given time.....say....4 years.
Of course, such disease, if not in the plant, can occur in the soil. Plants come out of nurseries in the best of health...it might take as long as 2, 3, 4, years or more for a plant to succumb to a disease that, right now, is not known.
A rose society of the State might be able to tell you if there is such a problem....or at the very least, do consult your State Extension Service, usually found at your STATE funded university or college.

Ann's idea to contact your county agricultural extension agent sounds like just the ticket to me.

We contacted our county extension agent once a long, long time ago, in trying to find out why we were having a problem with growing azaleas and rhododendrons in one particular area of the yard but not in others. With all the budget cutbacks they might not still do that, but it's a wonderful service. Someone actually came out to see the problem here onsite and didn't charge us anything to do it. The fellow who came out was extremely knowledgeable and pleasant to deal with. He almost instantly guessed what the problem was, semi-confirmed it by shifting a few plants within the ground from pushing gently on their stems, and sent some soil samples off to the state lab for confirmation: a moderately heavy infestation of nematodes (the bad kind of nematodes) that were eating away at the roots of the plants. I know this isn't your problem, but your roses might have something that a local county agricultural agent can diagnose just as quickly there. Our service was free, and I assume yours would be too, or at least not too expensive. Even if your agent isn't quite so sharp as ours was, you still probably wouldn't lose anything by spending a few minutes with him/her.

We've had two (very mild) cases of downy mildew here. I double-checked those photos and the roses didn't have any ridges on the canes. But perhaps ridges might have appeared if the disease had gotten worse, so telling you this might not be especially helpful--unless you can look or have pictures of the plants in different stages of coming down with the disease. If the ridges are there from the very start of noticeable symptoms, then it likely isn't downy mildew.

Your county extension agent is just the right contact for checking out Ann's other ideas regarding the potential for verticillium wilt and sudden oak death. Since they affect plants other than roses too, he might have had a better chance of hearing first about the presence in your area of those diseases before someone mainly concerned with growing roses would have. (I hope it's neither of those diseases. Fingers crossed for you.)

One other obvious thing to think about that I didn't think to mention earlier... Try analyzing in every respect the locations of each of the plants that have come down with the disease, and be sure to tell your extension agent about the locations of the goners and whatever connections you might be able to come up with from an analysis of those locations. Example: You have your 180 plants spread among 6 different beds, but all the plants but one that died recently were located in the front beds as opposed to from the back of the house (maybe more likely something like a gradual spreading of chili thrips?). Or, you have losses in all your beds, but they all are located near the new stone edging you've given your beds (maybe too much reflected heat added now?). Or, your losses are in front and in the back, but started out only in those beds that you added some extra bags of ___ to last winter to improve the soil (maybe the bags' contents weren't insect/disease free). Or, your losses are all in places less protected from an especially cold winter that might have set up the roses for succumbing to the first disease to come along. Or, the losses are all close to the swimming pool (spilled some chemicals intended for a pool there?).

One other suggestion that might help would be adding mycorrhiza, though it's some trouble when you already have the rose planted, and if it's something like verticillium wilt it might not help enough anyway. I once added mycorrhiza to two ailing established plants and I don't think I'd ever bother with that again, though I do still think mycorrhiza is overall a good idea and we use it when planting a new rose, when it's relatively easy to use. Those two roses I was hoping to help were virused and no amount of adding anything would have changed that. With this kind of (extensive and serious) problem that your roses are having, it might amount to a situation such as ours was. Or maybe not; it's hard to know, especially since the problem is still unidentified.

In favor of adding mycorrhiza... would be the firm conviction of someone very knowledgeable in organic gardening circles that plants with this added boost actually can more easily repel disease, and that it's not simply a matter of additional pathways for more water and nutrients (that's a good hedge during droughts and also especiaally severe winters). You can't know whether or not a plant thus reinforced can repel something as serious as verticillium wilt, but if you are willing to go to the trouble, it's unlikely to cause harm. At least what I did in adding it to our already-planted roses caused no harm at all that I could see. For adding to established plants, use something like an especially large and long pencil for punching holes in the ground. (I had an extra knife sharpening steel that was about the diameter of two and a half pencils and it worked perfectly.) You want to punch 4-6 holes in the ground all around the rose, starting from maybe 6 inches out from the center of the plant and directed at the center of the plant maybe a foot down. Pour a small amount of mycorrhiza into each hole, and then spread the dirt back into and over the holes. You're counting on at least one root making contact with some mycorriza, either directly from the hole placement or soon as it grows some more to that spot.

If you do decide to try mycorrhiza, be sure to never use any fertilizer that is higher than 1 or 2% in phosphate, as this will harm the mycorrhiza and might end up killing the plant that will have become somewhat dependent on the mycorrhiza working for much of its water and nutrients.

One last thought: I still think it's a good idea to water very deeply every now and then if you can, because of the potential for a soil PH that is too high in a low-rainfall climate. This would be true even if your roses have enough water available for takeup; what you want is a flushing of the soil downward to get rid of any salt buildup, if one might exist (though it sounds as if you're giving a good bit of water). In a desert climate, there ought to be plenty of dry soil underneath the plant to take up the excess coming from a heavy watering, and a system flush is unlikely to make matters worse. If this summer was a bit hotter there than in the previous years where you've not had these problems, a higher-than-ideal PH might combine with the main problem, whatever it is, and make it worse by creating extra stress overall. If you are able to fill some watering cans for spreading water around while doing some deep watering, it wouldn't hurt to add a tiny bit of cider vinegar to the watering can, just on a guess that your soil's PH is very unlikely to be too low already and that adding a tiny bit of extra acidity probably won't do any harm.

Big beautiful roots likely means no severe root-eating nematode problem.

That's all I can think of. In spite of lots of people thinking about your problem from afar, I doubt that you are going to figure this out via internet suggestions. But if possible, do post pictures.

The county extension agent idea is probably by far the most important suggestion to try.

Best wishes,
Mary

Chili thrips, like Japanese Beetles, haven't been noted as a threat in Arizona... yet.

Agility Mom, you keep mentioning 'organic' and 'Miracle Grow'. Using any oil-based agent, any fast-acting fertilizer, any chemical additive in high temperatures will harm your roses... organic or in-organic. We usually stay away from any sprays from May 1 thru October 15th. Some folks may use Wilt-Pruf or Cloud Cover but they spray early and may also erect shade structures over part of their garden.

We've got a short 2-week window in January that stays cool enough (70F max) to spray Volck's Dormant Oil Spray. If you can get your winter pruning done early in January, then apply a dormant oil spray immediately, you might be battling a scale pest. Scale can be nearly impossible to eradicate and they suck moisture directly from canes. At maturity, they'll look like a white crust. Some rosarians say it looks like hard water spotting. A dormant oil spray smothers eggs and spores but shouldn't be used in reflected light or near heat-retaining walls. My limited experience with scale is that it doesn't cause fast nor immediate death, though.

There are lots and lots of rose experts in the Mesa/East Valley Rose Society, including Master Gardeners, entomologists and ag-chemical experts. These folks grow roses in a climate and under similar conditions to yours.

I'm sure you mentioned this but were all these roses 4 years old and were they in the same section of the garden?

Could this apply to your soil???

Here is a link that might be useful: S. Arizona soil problems

Aside from all the advice you received in other posts above, you also may want to ask neighbors if they have any trouble with roses. Just a thought.

Yes, the roses were close to each other for the most part and were the same age.

There could be caliche in that area but it would have to be deeper than my planting holes because I have not seen any in that area. I really haven't found much to speak of in my yard.
I did test every hole that I dug for drainage before planting though.

The soil PH being on the high side would be a possibility and I will get it tested. I know that even though I water deeply and do periodic ground soakings, our water here has a higher PH.

I'm the only person around here that I know of that has roses. Most people here don't plant that much. They leave things more "natural" :)

Thank you every one for the great ideas and I will definitely contact the Rose Society and get the soil tested.

Right now, for the past 2 days, no more dying roses (I say that with my fingers crossed) but I know that could change so I need to get on it.

The MEVRS meeting is next Thursday night. I would suggest cutting a length of cane indicative of the problem you're seeing and take that with you. A fresh cane in the dying stages is better than a dead one cut a month ago. They may also ask you about the sun exposure, your regular gardening practices (water, feed, pruning, etc) and the cultivars. You may still get five different opinions, of course. Good luck and have a great time!