My guess, speaking as a gardener in Italy, is that soil alkalinity, and possibly soils that are heavy clay, have something to do with it. I tried a couple of Rugosas and they were complete failures. I don't know whether rainfall patterns, wet winters and dry summers, could be an issue as well. I have seen Rugosas a few times locally, but down in town where they have different soils and plants like magnolias grow nicely, unlike here.

@Melissa Northern Italy zone 8 ,

That is my hunch too, that it's more of an alkalinity/soil issue than an actual heat-tolerance issue.

I would think grafting and/or container gardening with adequate potting mix, would improve their ability to thrive in Mediterranean climates. But being a rose newbie, I could be completely wrong.

I guess I will find out in a few months, but I am curious to hear feedback from more experienced rugosa growers.

Agree with Melissa.

I've always had trouble with rugosas, and blame the soil. I'm near the southern end of a finger of moderately alkaline soil that runs down the Champlain Valley and into the Hudson Valley. (it also runs up the Mohawk, if anyone cares) 'Normal' pH outside the valleys is about 5.2. Mine is 7.2, and the Soil & Water people say they have seen test results as high as 8. This is an area that rugosas should love climatically. I've been keeping an eye out for rugosas grafted onto Laxa or Dr. Huey for a few years now, just to see how they would do, but those aren't easy to find.

Another issue you may run into is dormancy. When I was rooting a lot of roses, I kept them under lights in the cold basement their first winter. Most grew, and even bloomed, but some of the hardier types had issues with the lack of dormancy. I never did enough with rugosas to see if they were among those, but it is something to keep in mind.

Another thing to keep in mind is water. Groundwater in areas with alkaline soil is going to be alkaline. This is what did in my gardenia many years ago. It was fine for years around Philadelphia, where the soil has normal eastern pH. It even bloomed. Up here, it went into a slow decline, and died before I could get the acidification of the water right. Rainwater is an often recommended work around, but has obvious limitations.

Thanks @mad_gallica (z5 Eastern NY)

That is a very interesting point about the lack of dormancy. I hadn't considered that but that may well be something that causes people to say rugosas don't do well in warmer zones.

Then again, Wild Edric, doing just fine. I'm convinced there must be other rugosa hybrids out there that can handle it.

As far as water is concerned, it seems to me that this is kind of like the soil problem, but even easier to solve.

I have two products at home, one is pH up and the other is pH down. Depending on the needs of the plants I add a few drops of that to the watering can for that plant. So alkaline water can easily be corrected, just like you would for acid loving plants.

Of course if one has 400 roses on a drip system, that's not going to work. But for the average container gardener, it's easy to manage.

I have been told that rugosas do fine in my area (Northern CA, Med climate), but I tried two and they died fairly promptly. We do not have ANY "winter chill hours", and we do have clayish soil, although my garden is mostly "clay based loam", not clay, as it has been gardened for 107 years. I have a friend who gardens in coastal Maine, where rugosas are like weeds, happy & healthy & gorgeous, & large. They are so much inclined to naturalize on the coast that the locals call them "beach plums" - she did not even know they were roses when she first asked me about them. That is the sort of rose I don't really want to struggle to accommodate here, as I would always know how much happier they would be in a really cold coastal climate!

Jackie

Our soil AND water are hideously alkaline, and Rugosas and Multifloras pretty much fail here.

Using "bought" soil wouldn't help me much, because . . . well . . . water.

If I could afford to water them with bottled water . . . maybe.

Hmmm... Based on what you both are saying it really does seem to mainly be a pH/soil issue rather than any genuine heat sensitivity issue. This is really interesting to me, and quite encouraging, thank you both.

@jacqueline9CA For sure, I understand that with so many types of roses out there, if you are gardening in the ground it makes perfect sense to just go for the ones that do well in your soil! In containers, you have to provide everything anyway, so it's an effort no matter what rose class is planted.

@jerijen No need for bottled, just a few drops of pH down per gallon of tapwater. I've also used lemon juice. In both cases I check the pH of the resulting water before watering to make sure it's right. I only do this for my acid lovers, our tapwater pH is neutral here (reverse osmosis) and I find it very easy (but my garden is small).

And to both of you:

I am curious about your rugosas that failed! Which ones were they? Were they own root? Have you ever tried rugosas on an alkaline-tolerant rootstock?

My experience with Scabrosa in a Mediterranean climate on neutral to alkaline soil has been mixed. When it was young, it was prone to rust in spite of its rugose leaves--and I was afraid it was going to fail. It grew out of that, however, although it is still finicky. I'm not sure what I did to it last year, but many of its canes shriveled up and died. I cut those back, and it came back nicely this year. I posted a picture of it from a couple days ago on the "I can't post pictures thread." I don't think it will reach its full potential here, but it fits in nicely where I have it, underneath a manzanita and a wintersweet, with its prickly canes stopping squirrels and cats from running between my driveway and front walk.

No. I haven't tried trekking up and down my hillside with specially treated water. Nor am I piling ice around Gallicas to feign a winter we don't have. There are hundreds of roses that will grow here happily without all that. I'll stick with those.

Thank you for your insight about Scabrosa, @Formerly RBEHS Z10A/S17 . I'm glad your persistence paid off and you have good results with her now.

@jerijen I never tried to tell you what to do.

Quite disappointing to see my rose newbie questions met with sarcasm and condescendence.

Zone 9b, So Cal mid desert between the San Fernando and Antelope Valleys. In the 18 years of its existence, the temperature range endured was between 15 F and 115 F. Soil was native desert adobe, eventually HEAVILY amended with copious horse manure over many years. The wind was chronic and sun exposure was from nearly sun up until dusk. I WANTED to love Rugosas..

OR - own root

Budded and on what is indicated for those which were budded.

Basye's Purple Rose OR, chronic chlorosis but it lived and it spread like oatmeal on a two year old.

F. J. Grootendorst, Pink and White Grootendorst OR chronic chlorosis with rust and black spot from mid summer on. Old foliage refused to shed so the plant spent from mid summer to spring looking FEH.

Flamingo (hybrid rugosa, Howard, 1956) OR flourished, healthy, flowered like the weed it is and suffered NO fungal issues in all the years it lived there. '

Linda Campbell [MORten] OR flourished, grew and flowered without issue for years.

MAGseed sister seedling of Linda Campbell, OR, performed as well as Linda did for years except for the late season RUST.

Moore's Striped Rugosa [MORbeauty] OR occasional chlorosis with occasional rust.

MORjerry OR no issues for years

MORoserug" [7-90-4] OR no issues for years

Nigel Hawthorne [HARquibbler] OR no issues for years

Robusta (Rugosa, Kordes, 1979) [KORgosa] OR no issues for years

'Blanc Double de Coubert' OR chronic chlorosis with frequent black spot and rust outbreaks.

Conrad Ferdinand Meyer budded multiflora from Canada CHRONIC rust. Couldn't be sprayed as applying ANYTHING other than water on the foliage caused it all to turn yellow and fall over night.

'Hansa' budded Dr. Huey rust and black spot in waves. Not sprayable due to intolerance of anything other than water on the foliage.

'Roseraie de l'Haÿ' budded multiflora from Canada RUST, RUST and MORE RUST.

'Scabrosa' OR chlorotic much of the time but it grew and flowered.

'Rountuit ™ [MORtuit] OR no issues for years

Rugosa Magnifica OR occasional chlorosis but grew for years

Schneekoppe (Hybrid Rugosa, Baum, before 1984) [HANsno] budded from Canada rust and black spot late in the season.

Sir Thomas Lipton budded multiflora from Canada Regular waves of rust spring through fall and as with too many of them, the old foliage would NOT fall, remaining rusty and spotted until spring

Snowden OR grew rampantly with few flowers, spotted TERRIBLY. Finally culled.

Star Delight [MORstar90] OR grew and flowered with no issues for years

Topaz Jewel OR grew and flowered with some black spot issues.

And, plain old pink and white Rugosa, own root, RAMPANT invaders with chlorosis unless mulched with Ironite. Both rusted mid summer on until the foliage was stripped from them.

It wasn't surprising many of the Moore rugosa hybrids did as well as they did. They were bred and selected in a similar climate and the minis appear to have mitigated many of the health and chlorosis issues rugosas suffer in climates with more extreme heat and longer growing seasons than they evolved in.

All rugosas grow well here, Seaside. Our ph is 7ish as is our water. In Alaska they were totally dominating, while here they are among many who do well. Souv de Philomen Cochet got a bit chlorotic so I gave it some acid lovers fertilizer and it grows well.

We got intense heat last Summer with 41 days of 100 F or over. The rugosas always look healthy which is appreciated.

Seaside, I didn't mean it as sarcasm at all.

It's just that I've grown roses here for more than 30 years, and I've learned to MY satisfaction that the road to happiness is to grow what wants to grow here. If I were ever to move to the PNW, I'd grow Rugosas like mad. But not in my conditions. And not at my age.

@roseseek

What an awesome list! Thank you so much, I really appreciate it.

I guess I am forewarned now about Blanc Double de Coubert and Roseraie de l'Hay ! So far they have been slow growers, but healthy. I'll keep my fingers crossed that they can be ok through the summer. If not, I won't hesitate to throw them out.

Oh, Moore's roses... they are very hard to find in Europe, but there are a few places that sell a few of them, so I will do some hunting around and see if I can find any of his rugosas. The small size really makes them ideal for containers.

And I love Nigel Hawthorne! What an awesome combo of the hulthemia with rugosa. I might have to make an exception to my rebloomers-only rule for that one, it just seems like the most adorable pocket-sized rugosa! Flamingo looks great too!

@Sheila z8a Rogue Valley OR

Thank you so much for your feedback on Souvenir de Philémon Cochet! I hesitated for ages between him and BDdC. If Blanc fails to thrive I will give him a try instead.

I am totally going to try the acid-lovers fert on them too. Thank you for the tip!!

Blan Double De Coubert was always healthy for me inthe pacific northwest but I had condions it liked. im curouse how it would do in the south.

BDdC just made his first bloom here, so far it's handling the salty winds very well, which I expected, but the temps are still mild here (20°c today) so the real test is still a few months ahead.

Seasiderooftop, my soil is alkaline clay with a little loam on the surface. I've grown Scabrosa successfully, and Blanc Double de Coubert. Of course, our climate is much more humid in summer than yours. Whether this makes a difference I have no idea. I have had chlorosis in other roses, but not in those two. Another rugosa I saw in Tasmania with the most wonderful, jewel-like colouring was Rugspin. I have tried a plant here, but it has been very slow, but our last three summers have been very strange - sea mists, then smoke from bushfires, and this year rain, rain and more rain.

Another winner rugosa here is Agnes. I've read Sir Thomas Lipton is great in the South while not being great in Northern areas.

@titian1 10b Sydney

BddC just showed his first bloom here. He's new in the garden but is taking the windy conditions very well. The temperatures are still mild here (20°c today) so the true test of heat resistance is still a few months away. I will post updates here on how he handles it! I haven't been able to find Rugspin this year but I hope to be able to add it at some point! It seems like a great rose.

I hope you will have better weather this year!

@Sheila z8a Rogue Valley OR

I love the look of Agnes! There aren't that many yellows in the Rugosa class. The only reason I didn't go for her this year was because HMF says her repeat is iffy, but I think I will be trying her next year, she looks amazing! Does Agnes repeat reliably for you?

Haven't found Sir Thomas Lipton in Europe yet but I think I remember seeing him mentioned on Antique Rose Emporium's list, so I would think he is good in warmer climates! That is one extremely beautiful rugosa rose.

It's so encouraging to see that there are some rugosa hybrids that can do well in hot weather!

Agnes has occasional repeat, Seaside, but nothing like the Spring bloom. RdlHay repeats beautifully here and I agree that is a nice feature.

I forgot to mention that there's no real dormancy here, either. The Tea roses keep on blooming through winter.

@Bob Atchison - Pallasart - Hagia Sophia thanks for your comment and the word of caution about Antique Rose Emporium.

I'm sorry all of your rugosas died!

Of course I am curious to know which ones you grew, so I might make a note to avoid those.

Another question is were they in pots or in the ground and if in the ground, what kind of soil do you have?

I am trying to figure out what are the factors that might worsen/improve the Rugosas' odds of survival in hot weather.

I hope your weather will be less hectic! The twisters sound terrifying.

I hope your Fragrant Cloud will thrive!

@titian1 10b Sydney our conditions seem very similar, so I'm very glad to hear your Scabrosa and BddC do well, even without dormancy!