I grow Albas and Gallicas here in zone 2b Manitoba, Canada(Ag. Canada changed us to 2b but I refuse to listen!). I also grow several Canadian Explorers, Rugosas and some modern roses. Even some Hybrid Teas do okay here, although they might not be permanent fixtures in terms of decades. It is currently -23 Fahrenheit but we have a deep snow covering this winter so things should be fine. It's not true that once-bloomers have a longer bloom period here. All my once-bloomers bloom between mid-June and mid-July, and only the regular bloom period for each variety. It is true that we have a short growing season and we're grateful for our short, beautiful summers. The remontant roses that I grow usually have a large flush in June and a smaller one in September, with sporadic bloom in between. A lot of the less hardy roses that do "okay" for me will never get as big as they do down south. We do have some things going for us though. There are no JBs, it's too cold for them. We also don't have RRD and rarely see powdery mildew. I have only seen blackspot once. The positive for once-bloomers is that they are truly smothered in bloom when they're on, and the rest of the summer they tend to have very attractive foliage. Celestial is almost as pretty out of bloom as in. And Ispahan, Mme. Plantier is my very favourite rose too. It absolutely takes my breath away. :)

The real Northern European Once Bloomers -- Albas, Gallicas, Centifolias and the rest of the tribe -- won't bloom much here, and the don't live long, either. So I've given up on that form of frustration. And the Asian "once-bloomers" -- the banksiaes, and Fortuniana -- actually repeat a bit through the year. But we also have now a few big old Ramblers, and I don't know what they will eventually do. 'La Fraicheur,' 'Silver Moon,' 'Guadalupe Volunteer.' As the climate changes, we're beginning to get at least a little winter chill, so I'm hoping those Ramblers will someday put on a real big show in the spring. And I'd be remiss if I did not mention 'Indian Love Call,' a once bloomer that simply explodes with bloom for almost 2 months of spring, and follows up with a fall display of colored leaves. Even with a garden full of Evergreen Roses, there are some once-bloomers that fit right in. Jeri

Some can "rebloom" once they hit maturity. I often had repeat on my enormous Silvermoon in the desert. Though many can provide further flowers as Dr. Manners offered, some don't require the changes in weather to stimulate it. Some will seem to repeat because the spring like weather lasts longer. Along the coast here in Southern California, "spring" lasts for many months until the summer heat hits. There, the Banksiae roses flower for many months. A number of the old ramblers will follow suit. Some can be tricked into reblooming. I grew Schoener's Nutkana for many years and found if I permitted it to set seed, hold them for a few weeks, then completely dead head the plant, water it heavily and feed it, the plant repeated its spring performance as it thought it had over wintered and entered another spring season due to the loss of its hips, increased food and water. There are a number of reasons and ways to cause these things to happen. Kim

I don't grow a lot of non-remontant roses, and of those I do, the majority are house eaters. The length of bloom you get will vary from from one variety to the next, although I know some once-bloomers are valued for blooming up to six weeks or so. HERE, in TN, the average would be about three weeks from first bloom to last. My longest blooming roses are the huge wichuriana ramblers, which give me six weeks or so, but aren't hardy as far north as you live. But for roses like the albas/gallicas, your climate is a plus. You're in a much cooler climate, probably with a slower, more gradual warm up in Spring than down here. That would tend to increase your span of peak bloom. I'm guessing you might get as much as a month from most once-blooming roses (again, that's from first bloom to last, not necessarily full garden impact) . Also, the roses with truly spectacular flushes tend to bloom longer, just because of the sheer number of buds they produce. One type that comes to mind would be some of the Canadian Explorer roses. They aren't antiques, but are bone hardy and touted as re-blooming, but most don't, lol. My John Davis, for instance, blooms for a solid month here, and is COVERED for most of that time. Truly spectacular. It might squeeze out ten more blooms in the Fall. I would think it would bloom longer for you than it does here. Your best info will come from other northern gardeners (here on the Antiques forum, lol), and I wish you luck. You're not the first to go with once blooming roses to avoid the Japanese beetles! lol. John