I was so surprised surveying my garden to see a lot of live wood on the few young plants of ‘Weiss Immensee’ as well as multiple plants of its seedling ‘Fragrant Spreader’!!! I live in the Twin Cities area (zone 4). In addition, Bailey’s new yellow ‘High Voltage’ had a few inches of green above the soil line with new growth pushing, not only in my garden, but also at a bed of it planted at one of the Bailey farms! ‘Yellow Submarine’ and ‘Yellow Brick Road’, although healthy yellows and very nice, are routinely dead to the soil or below here.
Are there unexpected surprises others are finding with the hardiness of roses that are new to them?
I thought all the Bailey roses were field tested to be quite hardy to at least Zone 4. Perhaps where they tested them, they were. Or maybe simply “survival” was considered hardy enough.
That’s a great question. Some are definately hardier than others. With Baileys market going into warmer zones, they released some nice roses that would need insulation in zone 4/Twin Cities area to routinely survive. It seems they took into consideration performance in Oregon, where Ping bred them, as well as MN performance and performance at their other sites. Those that were marginally hardy in zone 4 that were good roses were still released. We’ve had multiple above average winters over the past decade. As more hardiness information builds, the tags and marketing are updated accordingly.
It’s a little early to tell yet as the buds are just starting to swell on my plants so I’ll know more as it warms up. But Highdownensis has much more good wood than I was expecting, being it is a cross with a Hybrid Tea. The canes are light brown and it was hard to tell how much damage they had, so I pruned them fairly high this spring(about 18" or about 6" above snowline). Every bud on the stems are swelling and I wonder if more of the canes would have survived had I not pruned them.
If I find any other surprises as they bud out I’ll give you an update.
David Z and Paul G … you are both in zone 4 … could you please tell me the coldest temperature you had experienced during this past winter? A rose that shows live wood above the snowline in zone 4 could prove crown hardy in zone 3.
We had what I would call a normal winter this past year. We had numerous days at least -20 F. but the lowest temp I saw this past winter was -28 degrees F. We didn’t have a lot of snow but what we had didn’t melt so there was constant snow cover all winter long.
Zone 3a Canada foothills, no not really, but I did get it confirmed this spring that two feet of continuous snow cover over out of zone roses with flexible canes that can be bent down in the fall is vastly superior protection from -30C and canker than my standard method of 6 inches of peat moss and burlap covering. Normally I lose the snow two or three times during the winter during chinook periods, but not this year for the first time in 10 years. Those parts of the nasty north facing gardens will probably have their best bloom … oh to live in the snow belt. The portland bed in the north that was covered with peat moss are nearly all wiped out with canker … this I attribute to being dumb and cheap by using old peat moss from the previous winter that I had stored in air tight bags after removing. I never have done that before in 10 winters and never again.
I did have one surprise in that R. Hemisphaerica which was not bent down and covered seems to have no damage unlike last spring - I still can not stack much confidence on it as this was only the 3 rd winter and it still has to leaf out.
However one observation if not common knowledge among hybridizers, or not preclude by genetics, is to consider R. primula (pickering version) in hybridization. My experience now after 4 winters is it is rock hardy in zone 3a - it actually has five foot long canes and only R. Glauca, Therese Buget and Persiana Yellow are in the same league for height of the roses I grow … I am so impressed with it it is not even funny, it is hardier in my garden than White Star of Finland, R. hugonis and a number of others commonly referred to as hardy in higher but cold zones.
Another one that I may be delusional about as it is only the second winter is the pickering R. forrestiana … not covered and can’t detect cane damage.
Can someone provide me the parentage of ‘High Voltage’?
I appreciated Riku’s comment about the cold hardiness of Rosa primula. I didn’t think it had much of a chance but have decided to trial it at the Devonian Botanic Garden rose garden (Zone 3) located near Edmonton, Alberta. It’s blooming in the greenhouse right now. I’m going to use it to make some crosses with Rugosas.
I have mentioned this before but now have more details about the Rosa moyesii growing at the DBG rose garden. It was on their 1988 rose list, so it has been growing there for at least 20 years. It is likely the same one that Robert Erskine grew successfuly (some winter kill but not much) in his Zone 2 climate. I’m going to send a small plant of it to David this fall for ploidy testing.
In the Parkland region of the Prairies, where there is usually a good amount of snow cover, I suspect we could grow a lot more Floribunda and shrub rose cultivars rated Zone 4 or 5 successfully. Particularly, of course, if they are on their own roots. For example, ‘Fred Loads’ survived and flowered relatively well for many years at the DBG rose garden. I noted the ‘Cardinal Hume’ Floribunda also did quite well as a grafted plant. Therefore, I promptly put it on its own roots and it has done well for a couple of years. Another cultivar that did well as a grafted plant was ‘Vineyard Song’. I was impressed with its excellent repeat bloom. The DBG has again acquired the last two cultivars, and it is my intention to get them on their own roots to hopefully improve their performance.
I must also mention the Rugosas ‘Linda Campbell’, ‘The Hunter’ and ‘Topaz Jewel’. Although rated Zone 4 or 5 and winter killing severely in a Zone 3 climate, they are crown hardy in Zone 3 and do very well. This is probably the ideal way to get repeat blooming true reds and also the yellow colour in Rugosas for a Zone 3 climate. A crown hardy but vigourous plant that blooms on new wood.
By the way, although ‘Topaz Jewel’ is usually sold as a grafted plant (at least in Canada), it roots easily from softwood cuttings.
Your rose 7A89 (Hawkeye Belle x William Booth) that you gave me has only tip die back on it this spring. The tallest cane is about 36" tall and it has live buds that are starting to grow to about 30" high on that cane. It was only hardy to the snow line last year.
With my limited experience so far with moyessi and it’s hybrids, I can say I would echo there is a good cane hardiness for Highdownensis, Marguerite Hilling, Nevada, Geranium and R. moyesii in my zone 3a garden.
Though they have not made my milestone of 5 winters yet in my garden they all have 4 winters and are not covered. However they are very slow growers for me. Personally I am a big fan of Marguerite Hilling.
Eos has only one winter but looks fine (some skepticism on my part as if it is the actual due to source).
I should of also said next winter Ralph Moore’s 4 Hulthemia hybrids pickering offered this year get trialed in my garden (Persian Autumn, Persian Flame,Persian Light,Persian Sunset)
I will cover the first year as they are too expenses not to at least coax through one winter.
Persian Autumn, Persian Flame, Persian Sunset, Persian Peach and Roses are Red were cane hardy to the tip in my garden this winter (5b/6a). The lowest temperatures we saw this winter were about -5 F.
That’s interesting Don… Do you think the cold hardiness of these roses was due to the persica ‘blood’ or the other ancestors? I was under the impression that persica might have been a little sensitive to the cold and like hot dry conditions (in general).
Simon, in the RHA newsletter last year I wrote an article on R. persica. It can be found up into Siberia, so some biotypes have winter hardiness adequate for use into the prairies of Canada. But I don’t know about the lines that were used to produce the current crop of hybrids. I believe they were from the general vicinity of Iran/Iraq.
So far I’ve not been able to find a contact in FSU to provide us seeds of northerly types.
Simon, I have no idea where the hardiness pressure comes from except maybe that deserts get very cold at night. The appearance of the humthemia canes might give a clue to thier hardiness. The green color is very fresh looking and quite shiny. The shine indicates the presence of waxes in the cuticle, so these may act to inhibit dessication, a good characteristic for both desert and cold conditions. Hardy canes tend to be woody canes, as well, and mature canes of the hulthemias are pretty woody.
Good news gentlemen/ladies or those who are interested , my time in the que is up and I receive Prairie Peace, Beauty of Leafland, Hazeldean and Madeline’s Choice this spring. If you cold zoner hybridizer’s have not seen Erskine’s Prairie Peace in real life like I have seen at Old’s College in Alberta … rest assured with what ever credibility I have an apricot rose is what you are missing,- a true beauty and marvel for color in hybridization for super cold zones . Gad’s as I mature in my rose collection how naive and belated I have been in recognizing the greatness of the Canadian Prairie private hybrization effort … I also incldue in laurels a Mr. Hansen collection effort (grow alika) and a crab Dolgo - Alika a true gallica place holder titan in zone 3a.
Come on gentlemen/ladies , lets get going and get me some more that excite me likw Erskine;s Praire Peace I have another 20 years on earth,
Riku, it’s good to know of your excitment A few years back, I had worked a bit with ‘Hazeldean’, I have numerous resulting seedlings and hope to get my first blooms this spring or next.
Paul Olsen, I have often considered using the ‘Hunter’, it has very good bloom color and form. I’m now also interested in ‘High Voltage’ …
A few years back, I had worked a bit with ‘Hazeldean’, I have numerous resulting seedlings and hope to get my first blooms this spring or next.