Roses that act like it is 75F when it is 115F:
Jeanne d'Arc (noisette)
SdlM
Goeth (moss)
Souvenir d'Elise Vardon
Now the blooms might get a little crispy in the afternoon when the heat really gets to cranking...

Lots of damage on most of the roses, yellow leaves, dieback, death.

This has been the worst year ever.

I am losing my patience with Mrs. Woods Lavender Pink Noisette.
It's not that it's taken her 4-5 years to bloom ... I can handle that.
It's that the blooms she has produced have been balled nastily, and that while the foliage is clean, she has a lot of unattractive mildew around the peduncles. In a rose of this sort, these things matter.

She is on probation.
I've got happier roses to put into that spot.

Jeri

Rosette Delizy and Abraham Darby both continue blooming in extreme sun, heat and humidity, smaller blooms true but still welcome. Once a week they get drip irrigation.

Autumn Sunset also just burst into bloom after applying some manure.

Denise

I know how you feel. I live in a semi-tropical area, and when I get frustrated with roses I try to stop and remind myself that they are mostly native to temperate zones.

We humans are the ones asking them to behave in tropical and/or desert conditions. And while some might "adapt", that's not exactly the same as thriving and always looking their best.

But, I keep looking for and trying different varieties, too. It's as fun as it is frustrating.

Jeri, my Mrs. Woods LPN for some reason bloomed quite a bit sooner than yours but had mildew on the peduncles, leaves and even stems. Talk about ugly! Earlier in the year she had gorgeous blooms but the mildew took care of that too. I'll give her another year but after that....

Ingrid

Ingrid, it is not as hot here of course as it is at your place, but to my surprise Rhodologue Jules Gravereaux is really cranky already regarding the hot weather. Its flowers look wilted, even though the rose is watered well. The subtle coloration of the blooms of this tea rose just look washed out, there is nothing subtle and beautiful left, the blooms are just ruined by the heat.

On the other hand own-root Mister Lincoln just started to thrive in the heat, it almost looks like this rose needs heat to be its very best. Yolande d'Aragon doesn't seem to care and is growing happily and producing many buds, and the flowers don't crisp (yet). When I looked closer at her I realized that this rose has more petal substance than other HPs, which might explain why it is holding up. William Shakespeare 2000 also loves the heat pumping out a lot of flowers with a wonderful fragrance. It is going to be interesting to see when comes the breaking point where no rose likes the hot temperatures anymore and who is under the "finalists".

Christina

Here is a link that might be useful: Organic Garden Dreams

Bishop's Castle. It hasn't even been hot, just warm, and the entire first flush is crunchy. Looks terrible. I'll give it another year.
Julia Child looks great.
Renee

Some Roses that thrive in the heat for me include:
Joasine Hanet: The rose may suffer from some odd iron deficiency (partially because it needs more consistent feeding than I provide), but still keeps pumping out blooms in the high heat.
Fairy Dance: This evening I took in a spray of about 50 to the Celebration part of our local rose society meeting and it will pump out blooms until winter chills.
Papa Hemeray: The blooms keep on coming with nary a diseased leaf or a shriveled one either.
Aptos: (Dr. Robert Korns). And Jeanne d'Arc.
Some that do not like the heat at all:
Rival de Paestrum
Cinco de Mayo
Dream Come True
La Reine (the rust is forever).
In general my HPs go dormant or rust or both in the high heat.
Jim D

I frankly don't expect much out of my roses in the summer heat. We are in a three-year drought and the temps have been in the triple digits here for days. However, Belinda's Dream, Christopher Marlowe, Mrs. Dudley Cross, Bon Silene and Elina have kept on pumping out beautiful huge blooms. Most of the others have blooms that are significantly reduced in size and are not blooming in large flushes like they do in cooler weather. However, most of them have healthy foliage and that's all I ask in this heat. I'm certainly not blooming either. I only go outside early in the morning and after 7:00 in the evening.

In general my HPs go dormant or rust or both in the high heat.
Jim D

&&& In general, here nearer the coast, our HPs go dormant or rust or both in the summer, whether we get heat or not. (Our location has, normally, much less heat than JD's.)

The exception to that rule is "Grandmother's Hat," (which may or may not be an HP, I suppose) which does not rust at all except in very rare cases, late in the year.

Jeri

imagegardener, I find it interesting that your Abraham Darby is doing well in the heat whereas mine fainted at the slighted raise in temperature. I love that rose so much, even moved it to a shadier position, where it then got rust. Oh well.

Christina, that's good to know about Rhodologue since I think it's very beautiful but obviously here it would be a pallid version of itself most of the time.

Renee, interesting that you're just now having your first flush of Bishop's Castle. Mine about a month ago in the cooler weather was spectacular. Right now it's setting new buds and I'm curious how those will turn out.

Jim, I've had bushes of Joasine Hanet and none bloomed much if at all in the heat, or much after the spring flush period. The leaves were always a light green. I think it needed more TLC and water than I gave it.

Jeanne d'Arc is listed by two of you as being good in the heat. Must look at HMF. I'd love to get a lot more responses since I've started a list of heat-resistant roses.

Ingrid

Not doing well - La Reine. She spotted horribly and balled this spring and I had to cut her back. I don't spray her because she is so close to the shore of my pond. Gonna move her in the fall. She doesn't repeat to speak of. Also looking pretty poor around this time every year is an unidentified pink polyantha. Usually a good spring flush and never reblooms.

I am expermenting with giving repeaters twice daily showers of cool water. Showers are brief, enough to wet the leaves. I water the roots deeply in a separate effort. It started with worry over spider mites once the temps got over 90. The leaves dry quickly and spot doesn't seem to be a problem, though I do spray. I do it in hopes to keep the leaves clean and hydrated. It is hot here but also humid.

I took these today of what looks pretty good for 90 degree temps. Unfortunately, none of my antiques are in bloom right now, although Duchesse de Rohan has two buds forming. Baronne Prevost, Ghislane de Feligonde and Mozart have a few blooms but fading. General Galleini is done with his second big flush.

Here is White Knight. Not an OGR, but an obscure old HT:

{{gwi:284027}}

Chrysler Imperial, blooms are a little smaller but still smell good:

{{gwi:284028}}

And Pope John Paul II. Can't wait for these to open:

{{gwi:284029}}

The half OGR 'Belinda's Dream' is perfectly happy in the heat. Ditto for hybrid Bracteata 'Precious Dream' which I have right next to the blazing concrete driveway. It loves it.

Poor 'Barcelona' can take the heat, but those black-red flowers cannot. Crispy.

My 'Bishop's Castle's hold up the to the heat very well. Perhaps because they are 3 or 4 years in the ground now? Or it doesn't get that hot here?

I must say my near 60 HTs with a few floribundas and grandifloras, plus my one Austin - Mary Rose, all do perfectly fine in the heat (I do water daily when it's over 90 degrees). Wonder how much has to do with the fact that every one is on Dr. Huey rootstock?

Ingrid

My Abe Darby is one of the few grafted onto Fortuniana, perhaps that makes a difference, he is also putting out new growth and looks shiny healthy. Rosette DeL is own-root.

Denise

I have teas, chinas, noisettes and hybrid musks and I have found that the noisettes are performing best in the heat. I am especially pleased with Natchitoches Noisette, Blush Noisette, Jeanne d'Arc, Mary Washington and Fellenberg. Among my hybrid musks the one doing exceptionally well is NurMahal. My chinas are producing smaller blooms, but the plants themselves are doing fine. None of my teas (M. Tillier, Mrs. Dudley Cross, and Safrano) are blooming very much at all.

Ingrid -- Joasine Hanet appears to object to alkaline conditions. She needs (here at least) some soil sulfur.
First chance I get . . .

Jeri

What do folks thinks might be the impact of Rose Mosaic Virus on heat tolerance in roses? Could roses that are infected with one (or more) or different of the viruses involved in Rose Mosaic just simply be weaker plants in general and thus less able to tolerate high temperatures? I know I've read they don't do well in cold as the viruses multiply more in cold weather, but I'm wondering whether when the rose reaches the time of year, or lives in an area, where it is quite hot, it is just too sickly to handle that extreme heat even if the virus(es) aren't actually multiplying at that time. I know I don't feel too great with the flu in summer, so......

If I'm remembering what I've read that Henry has posted, the heat surpresses the virus, bolsters the immune system and the plant outgrows most of the effects. Remember, to "clean out the virus", they grow the plants under high heat lights for propagating material. While the plant may be weakened from combined effects of various ones and from cooler times, it seems it should recover and gain some lost ground back during the heat. Unless, what it receives, or doesn't receive, during the extreme heat is enough to cause sun scald, potential Flat Head Apple Borer infection and eventual death. I've had those, too. Kim

Tessiess-- hot weather suppresses mosaic virus so there is less of it in the above-ground parts-- although your suggestion could still be true.

We don't have high heat here, but 'Barcelona' (aka Francis Dubreuil) burns in the sun worse than any other rose I've grown. It's overall a good rose for me, though.

Thanks for mentioning Henry. I'd like to know what he thinks about this. I've found his posts very interesting! I started wondering about all the variables in peoples' gardens and what impact those variables might have on RMV and whether some may make it worse.

I'll tell you where I'm coming from. In people we wouldn't expect someone with the flu and a high fever to win the Boston Marathon, especially in the heat....and I've been watching some marathons on tv lately.

The other thing that started me wondering has to do with what I've been doing lately. I've been donating platelets at a cancer center to patients undergoing bone marrow transplants. Well when I donate, I can't have a cold, the flu, nothing, no infections, because the patients in chemo have no immune systems and any opportunistic infection can just take off and may kill them.

So I wondered what about plants, say roses in Southern California with RMV? How would they fare? In the parts of the year when it is cooler and the RMV virus or viruses (if the plant is unlucky enough to be infected with more than one) are happily multiplying and making the plant weak. Is this happening in a vacuum, or are there opportunistic infections making matters worse? So then I wondered how these RMV infected plants handle rust and blackspot for example in comparison to their non-infected brethren? And then I wondered if throughout the cooler parts of the year when the RMV is rampaging and suppressing the plant's immune system, how much also might the coolness and/or humidity also be promoting blackspot and rust, in these susceptible plants, and further weakening them? So by the time the heat of the summer months is reached, RMV may not be able to multiply but just how strong is that poor plant by then? Does it have enough time to recover? And can it even in the stress of *very high* heat? Maybe if it has some shade, some protection, but extreme heat on a sickly thing? Depends on the garden conditions?????

So I could be all wrong, but I'm considering how many of the roses that aren't doing so well in difficult heat conditions are also harboring multiple infections at the same time?

I understand what you're saying about the virus weakening the plant, making it less able to handle stressful conditions. But, like michaelg, I've also heard that heat kills rose viruses. In fact, isn't that how roses with RMV are "cleaned up"--with heat treatment?

Hope Ingrid doesn't mind us going off on a somewhat related tangent!

Tessie, I think you're heading in the right direction with your thinking. Probably, the simplest explanation would be anything which reduces either quantity or quality of foliage would result in malnutrition. Malnourished anything is more susceptible to opportunistic infections, and like those with compromised immunities, it's the opportunistic infections and/or conditions, which usually kill you.

I've seen roses so badly infected with various virus, there was very little "green area" to the foliage. I'd think a reduction in the chlorophyll area of 50% would be comparable to cutting half the foliage off as far as food production is concerned. It's pretty logical that such a plant would be weakened, stunted and more vulnerable to sun scald, fungal attacks, freeze damage, etc. We're fortunate here that our heat helps to suppress the negative effects of infection so the plant can attempt to overcome them. Over time, though, varying greatly with innate vigor of the variety in question, that could result in the plant finally just dying.

I studied the old HT Autumn at The Huntington for many yeas. It is such an amazingly vigorous plant, even own root. The foliage was heavily paisley ed with virus symptoms and we'd joke that the virus was likely Nature's way of preventing that plant from taking over the garden. It was huge, strong growing and always full of flower, even in the shade and root zone competition of the enormous old Hollywood Junipers. Compare that to a friend's mother's Amy Vanderbilt which had grown in her rear garden since the early sixties. Amy isn't a vigorous rose to begin with. As badly virused as it was, each year it begrudgingly eaked out a few inches of growth with very few flowers. Which came first, the chicken or the egg? Was Amy more susceptible to the virus due to her inherent lack of vigor or was her lack of vigor the result of the severity of her viral infection? Kim

Oops. Never mind. I found the article I was half-remembering. (Link below.)

"The potted plant is placed in a controlled-environment chamber, where the temperature is held at a constant 38�C (100�F) for 21-35 days. The heat treatment does not cure the plant, but RM-free material can be obtained as follows: Axillary buds from the treated plant are budded onto RM-free rootstocks. Most of the axillary buds on the heat-treated plant will be free of RM. Once the new budlings are growing, they must be tested to insure freedom from RM, a process known as "indexing."--Malcolm Manners

Here is a link that might be useful: Rose Mosaic Virus Disease

>during the few minutes I've ventured out I've been casting a jaundiced eye at those roses that look lovely in the cooler seasons but have now pretty much lost their charm. Admittedly that's quite a few but certain ones stand out, such as I... Duchesse de Brabant...

Our Duchesse de Brabant isn't looking quite so wonderful nowadays either. It's still extremely healthy, but the blooms just aren't holding up well here in the heat. It has been kept well-watered, so that's not the problem.

Best wishes,
Mary

I noted a mention that Abe Darby is doing great in the heat somewhere. Mine is going great guns in Portland after a wet spring. Versatile rose, no? No disease so far, and lots and lots of big happy blossoms. The blooms are gorgeous and smell great. How can anyone not love this rose (I realize some don't, but I can't understand it!).

OK, I don't love Abe Darby because of its frequent vegetative centers and high susceptibility to blackspot. Also many petals had brown spots from botrytis petal blight, so I'm surprised to hear that it liked the cool rain in Portland.

I can understand how some love Abe for the color, fragrance, flower size, etc. I come in too frequent, too intimate contact with one at a friend's house and I don't care for it. The color is too unstable and often ages quite poorly. There is a huge tendency for black spot and occasional rust in this climate and the prickles are horrid. It rips me, extracting its required allotment of blood every time I encounter it. Here, it's best treated as a climber, which it really is, but too many plant it as a free standing shrub which it really isn't suited for in this climate as it grows like a climber here. Kim

It was disease-free for us, near the coast, but the plant here was never sturdy enough to give good support to the enormous blooms.
When a gopher ate its roots, we didn't replace it.

Far better in our area was Emanuel -- "one of the Austins which has been replaced." (Replaced by what?)
We grew that one for many years, and found it to be fragrant, disease-free and a good bloomer -- in a fairly difficult location.

Jeri

Far better in our area was Emanuel -- "one of the Austins which has been replaced." (Replaced by what?)

LOL !! LOVE that!

Replaced by a rose that is still under patent. It's an economic role rather than a garden role, so it could be any color (etc).

'Emanuel' is one of the very best Austin's for hot, dry gardens. 'Radio Times' is another good one, as 'The Reeve', 'William Shakespeare', 'Swan' (a magnificent Rose) and -whereas short lived in summer-,'The Alnwick Rose', 'Glamis Castle', 'St Swithun'...

Many Teas and Chinas crisp relentlessly here in summer, only a few are still good: 'Mme Falcot' (ex India), 'Mrs Dudley Cross', 'Le V�suve'. 'Odorata'/'Spice' shrink under hot sun, but it's continuousely in bloom.

However, some Roses seems to wait for summer to show up their beauty. I can't succeed to see a single open bloom in Spring from 'Tipsy Imperial Concubine' (I use to call her Tipsy Imperial Artichoke'!), 'Clothilde Soupert', 'Leveson Gower' and that big Bracteata Hybrid, 'Alba Odorata'/"Maria Leonida". But they are a magnificent sight in July and August. So I still grow them and enjoy them when other Roses have their bad time.

I'd like to add that heat resistance in Roses -as in all other plants- is not only a matter of temperatures and humidity. The kind of soil they grow in is a very important element to consider, as it's able to influence a great number of different aspects in plant's physiology.

I saw recently in a garden in Catania, Sicily, a huge 'Felicia' growing in an abandoned corner: she was in full sun, bare earth, no watering, near a orange grove. And it was early June, with average 30 �C. The plant, full of perfect green leaves, showed a huge mass of big, full clusters of fragrant blooms, as large as I only saw in England. The same rose suffered by midday in my garden in May with no more than 26 �C, watered almost dayly, and my blooms where less than a half the size in Catania.
So... WHAT it was the "x factor"? The soil! And, overall, a whole different micro-climate.

In Catania, they are blessed from Mount Etna influence and that means: to equal day temperatures, lower night temperatures; a rich, deep, ultra-fertile volcanic soil; a typical, very thin "mist" who lightly veil the sky in the afternoon, protecting the plants from being scorched by sun.

That 'Felicia' was surely sinking their roots deep into that fertile soil, finding the right amount of water, their leaves protected by air humidity and night freshness, enjoying their settled climate conditions, whereas mine was fighting with a thin, granitic soil, under a sharp sun, and -maybe more important- with jumping climate conditions: humid nights followed by dry, windy days... what -I've experienced- the roses seems to hate the most.

Hope, as usual, this should help.
Maurizio

In my super hot summer climate, nothing much blooms and I worry about what young roses will not survive the summer. The first summer is the hardest and the second summer sometimes kills a few. After that, the ones that have survived seem to do fine. Few blooms in the summer though; I dont' expect them to.

The ones that seem to survive ok in the summer are:

Arcadia LA tea -- it's in a semi shady spot (good for here in summer) and gets alot of water
Alister Stella Grey -- grows like a weed here; almost invasive
The Cochet tea roses
Catherine Mermet and Bridesmaid
Mrs Dudley Cross -- is actually blooming right now though the blooms are small. It's about 3 yrs old though so has survived the summers when small.

Struggle in the heat:

The tea noisettes!! I'm soo frustrated...I thought Chromatella was going to be ok but has now only one cane. I've lost Marechal Niel a couple times and a couple other tea noisettes. Reve D'Or does ok here though and Duchesse D'Auerstat is looking pretty good so far.

Some Chinas: Rival de Paestrum is looking very poor right now. Chinas seem to struggle here generally

Some teas struggle here: I've lost 2 Mrs Foley Hobbs and Mme Bravy is looking poorly right now. Of course, the hard to find ones...

A surprise great rose has been Huntington's Papillon, from Vintage. It grew rapidly after planting and has been very healthy. Beautiful magenta blooms. Very lovely plant. Seems fine in the heat; this is it's second summer.

Maurizio and Jasper, thank you so much for your detailed answers, which I really appreciate.

Maurizio, your comments about soil and microclimate are very interesting. I also had Felicia, and garden on decomposed granite, and this rose just withered away. Mrs. Dudley Cross, Le Vesuve and Spice do well for me too, although the Spice blooms do get tiny. I think Belinda's Dream and Mrs. B.R. Cant will do well for me, although at the moment I'm removing every single small bud in order to encourage them to grow taller. Miss Atwood is growing very quickly, although her blooms fry in the heat. Leveson-Gower strangely has been blooming much sooner than the one you mention. Perhaps my heat trap of a garden spurs it on to bloom sooner. I don't believe Mme. Falcot is available here; I'll check further.

Jasper, I haven't looked into the Cochets since they seem to be so extremely drooping. I'm surprised they do well in the heat since the petals look very delicate. I've also not had great success with the Chinas. I do have a large Mutabilis but summer is not its shining hour. Vintage seems to no longer have Huntington's Papillon. A pity, since I really liked your description of it. Rival de Paestum never took off for me. Mrs. Dudley Cross does well for me, especially the new plant that I disbudded completely until now, since it's reached a good size. Taking off all its buds really seemed to help it to grow extremely quickly. Perhaps you might try that on your young plants, if you haven't already. I'm also going to fertilize my roses with alfalfa for the second time this year to see if that will help them through the summer season.

Ingrid

It used to be fairly common on plant groups to have "round robins". Things not in commerce were propagated and traded or sold for the cost of postage. For roses like the aforementioned Huntington's Papillon, why not propagate a few if your plant is large enough, then in spring, offer them to list readers for either trades of out of commerce roses they have propagated or for the postage?

Flat Rate Priority is getting things across country in three days pretty regularly. Shorter distances are much faster, often over night. A small box costs $5.20 plus .70 for tracking if desired. A medium size box, which can hold a LOT of material, is $11.65 including tracking. I'd think a nicely rooted China cutting should fit into a small box easily. Several would fit into the medium.

No nursery can carry everything, and there are fewer and fewer of them around. I wouldn't propagate things Vintage or someone else has listed as available, but for truly out of commerce plants, it's the only way to spread things around and prevent their loss. Yours may be growing well today, but all it takes is a misplaced handful of fertilizer, a failed sprinkler, an over zealous lawn mower, gopher, dog, etc., and something which has been common, dwindles down to one or two threatened plants.

I think many will be surprised to see how many "staples" are going to become only available as "pass along plants" fairly quickly. Kim