nobueno, I have had no trouble with hardiness of Japanese plums here in Denver. The issue is not hardiness but bloom time; we usually get frosts that kill the blooms. I have Elephant Heart and Satsuma and my neighbor has Santa Rosa. We have had good crops the last few years. The European plums, especially my Shropshire Damson, bloom later and therefore avoid the frosts. I would have to say that it sounds like you are wanting a Santa Rosa. You will need a pollinator for it though. A Japanese hybrid would work well. But you should be prepared in case of frost at bloom time.

Folks, Gracious, Pembina, Toka (and Kaga are almost identical) and Kahinta are much better (in my opinion) than Lacresent, Underwood, and Waneta for the "superhardy" plums. Pembina cracks readily, but it is so prolific even if 80% crack you still get a good crop. We use the cracked ones to make "Smiling Plum Jam" which sells very well. Pipestone is much like Pembina (flavorwise) but larger and drops when ripe so you have to pick them before they are ready and let them sit a day or so. Underwood is the hardiest, but has a very sour skin and less flavor. Waneta can be wonderful, but is astringent until perfectly ripe then it drops, and the fruit ripens over a long period so most of the fruit drops. I pulled out all my Underwood, Lacresant, and Wanetas this fall as they were taking up space I could use for better fruit (and got a run of firewood out of them). Opal does well here but was affected by the freeze of 2012 (1/2 of my trees did not have fruit that year) so it is not as bud hardy as others. Ember has been a total disappointment, little fruit (but the fruit was a pretty yellow orange), lots of disease (for some reason lessor peach borers love them), and the fruit was not good enough to put up with the lack of productivity, so I pulled it out as well. Mt Royal (round blue European about 1") is a very hardy plum, tastes good and is prolific I would recommend it. Stanley is pretty tough as well but need heat in Sept to ripen. In colder climates date of ripening is important. Even if the temps get to 70 during the day in Sept, they are only there for a couple of hrs which can lead to the fruit not ripening and lack of sugar and flavor. There have been years here when the Stanleys and Empress plums have not ripened due to low temp in Sept. So it is best to pick varieties which ripen earlier if you are in the North. Eric

Summer, if you can grow Knockout and Carefree Beauty roses, you can probably also grow the nice variety of Easy Elegance Roses, a lot of Kordes roses (like the Vigorosa or Fairy Tale series of roses), and quite a few Buck roses (just not his lavender varieties). I've had good luck with a lot of the Austin roses, and some like Teasing Georgia and Lady of Shalott are in zone 4 pockets of my yard that should work for you. TrueBlue is right that my Barcelona/Frances Dubreuil is at least 7 years old and is cane hardy most years, though it needed a lot of trimming last year. It has the advantage of being the most intensely fragrant rose I've ever grown as well. Being a zone pusher myself, I've killed at least as many roses as I've overwintered successfully (I keep records - it's almost exactly equal at this point). All you can do is try things that work for you in your yard. A good rule of thumb is that something labeled a "shrub" rose is likelier to be hardy than a traditional Hybrid Tea, but there are a lot of exceptions to that principle. Obviously your Morden Sunrise wasn't as hardy as it should be for a shrub, but that may have related to being a tree standard as Seil noted, not a bush in the ground where you can bury the graft and protect it from the harsh winters. Bottom line is not to give up on roses, just broaden out the range of what you're willing to try. And don't necessarily trust your local vendors if they want to sell you a lot of Hybrid Teas - some garden centers in cold zones are thrilled to sell you HTs because they function as annuals and you have to replace them every year ($$). I have hundreds of HTs that overwinter fine, but it's a learning process to find ones that will overwinter easily in zones 4-5 vs. those that fade at the slightest hint of cold and are truly the zone 7 they are advertised. Cynthia

>>I wonder If I graft the japanese maple onto a regular hardy maple in my climate?Grafting I'll use the example of roses here. Just like japanese maples, most roses are not hardy to zones 4 and lower. The are zone 5 and up. Hybrid tea for instance are not hardy but they are grafted onto hardy roots. Unfortuntely, this doesn't make them hardy in zone 4 and down, we have to protect them heavily so they will come back the year after and even then you run the risk of loosing them. Not because the root system is in danger but because the grafted part is. But even if you loose the grafted part during the winter, you still may have roses that will emerge from the root stock, below the grafting point. Of course, they wont be the same hybrid tea that you bought since that part died, but a hardy rose from the plant on which it was grafted. I would say the same rules would apply to japanese maples grafted onto hardy maple roots. You probably know the Explorer Serie roses. These roses are hybrids but are not grafted, they use their own roots to grow from and they are hardy to zone 3 and some to zone 2. I have 5 of them doing very well and they never needed any kind of winter protection and I never even thought about giving them any either (zone 4b QC, Canada). Why is this? The crosses were made between hardy species and/or cultivar from the the start and the breeding was done not to impart hardiness in the first place but to develop other caracteristics such as colors, trailing habits, short plants, diseases resistantce, etc. They probably used less hardy roses in their breeding program to bring in some new genes unvailable otherwise. Hybridizing If you cross two zone 5 plants like two acer palmatum, you'll end up with a bunch of other zone 5 plants. But if you cross a zone 2 plant with a zone 4 plant, you will probably end up with 80% of the plants hardy to zone 3, 10% hardy to zone 4 and 10% hardy to zone 2. Then if you take one of these new zone 3 hardy plant, roses for example and cross it back with a zone 2 rose, you may end up with a 50% zone 3 and 50% zone 2 stock. And if you cross back again one of these new zone 3 rose with a zone 2 rose, you may end up with a 75% zone 2 - 25% zone 3 ratio. These same rules would also apply to maples making crosses between 2 different species, one of them being the japanese maple for the first cross. The difference is here: in the example of roses I took, the desirable plant and the one used in every cross was a zone 2 and the goal was to bring a zone 4 plant to zone 2. With every cross I did I added some zone 2 hardiness to the gene pool. With the japanese maple, we would be working against the odds, the desirable plant and the one that should be used in every cross is a zone 5 plant and that would bring a zone 3 plant to a zone 5 only. And if I added more and more zone 3 maple, I would be loosing more and more of the japanese gene pool. Either way leads you away from the wanted result. And we haven't even said a word about what could be recessive of dominant in these crosses, which is also a very important factor to keep in mind. This can be observed in the new clematis hybrids that are reaching the market these years. Old clematis were hardy in zone 4, but crossing them to warmer growing one has yielded many new very desirable hybrids, but only hardy in zone 5, 6 or even 7. We have gained in beauty but lost in hardiness. In a word I don't think grafting would be successfull in the way you would want it to be. And breeding wouldn't work quite the way you would want either from what I understand from what you said. These are two of the reasons why I said that selection was a much better approach in your case. It is not an easier or shorter one way to do, only a safer one. Hope this helps!