Hi All,
I’m brand new here and just getting started with rose hybridizing. My interest is primarily to learn and have fun but one path I want to pursue is working with North American species. My plants are all pretty young so to get practice with growing seeds, germination and seedlings I ordered some seeds from reputable wild seed providers (not Ebay).
I am looking for advice on the best cold stratifying procedure for North American species seeds, in particular Rosa blanda and Rosa virginia. One of my seed sources, Prairie Moon Nursery, advises a double cold stratification, essential first cold, second warm and third cold again. However I can’t find any other documentation about doing a double stratification.
Any helpful advice or experiences would be greatly appreciated. Thanks in advance.
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Welcome!
I can’t speak to r. blanda but I grew a lot of r. carolina from seed last year, which is very closely related to r. virginiana. I just sowed them in a planter outdoors at the end of October, then they all started popping up when the weather got warmer 3-4 months later. I think had around an 80% germination rate.
I love Prairie Moon but their rose seeds have been hit or miss for me. I’ve also seen them recommend double cold strats for several plants which I have grown with anywhere from 3 to 0 months of stratification. Bear in mind that different climates tend to produce different results, so if you have enough seeds you might try taking a few different approaches.
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That’s very encouraging, thanks. I have a group in the fridge now with about 10 more weeks to go. With your advice I figure I’ll go ahead and try them even though it’ll be late in the season to start. I’ll try another batch with your method this fall too. I’m in Brooklyn so solid 4 seasons and we get cold but not crazy cold winters. I suspected Prairie Moon might be throwing germination codes at seeds by very broad categories and not being too species specific.
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In my experience the best outdoor germinations occur when the daytime temps are around 60-70 and the nights dip into cooler temps above freezing. The fluctuations seem to trigger whatever hormones tell the seeds that spring has arrived and it’s safe to sprout. Rainfall appears to be a big trigger as well. They also seem to lose almost all productivity once it gets into the 80s, but until that occurs I wouldn’t consider it too late in the season to experiment.
Of course this year the winter was so mild and the spring so absurdly hot and dry that my outdoor germination rates have been terrible, but I guess that’s just the world we live in now. Fortunately species rose seeds are a lot more forgiving and possess a much stronger will to germinate than modern hybrid seeds.
The main thing I think is to learn what happens in your climate. The old cliche rings true that it is more of an art than a science. The hobby is obscure enough that there’s already a shortage of information online, and oftentimes when you do find a specific discussion it’s from someone in a wildly part of the country or it’s from 20 years ago when the climate was more stable and predictable.
It’s kind of becomes a fun part of the craft, all of the trial and error it takes to figure out your unique way of doing things. I’m still too new at this to give out much advice but I can confidently say that the best thing you can do is embrace as much trial and error as possible.
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If you wait till mid-June to plant Rose seeds, the heat may deter germination. Roses prefer to germinate early in the season when temperatures are still very much on the cool side. Anything that repeatedly exceeds 75-80F will signal the seeds to stay dormant and wait till next year.
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Thanks Paul. That’s good to know, I had not come across that information yet.
I also got some seeds from Plant World Seeds in the UK for Rosa canina and Rosa gallica officinalis that they claim are already cold stratified. I went ahead and started some of them a few weeks ago as an experiment. Maybe I’ll get lucky and have a few to start practicing with.
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Thanks @KDickinson. Experimenting is my thing so this should be fun. I also breed freshwater aquarium fish which takes all kinds of trial and error too.