Spinosissima seedlings take two years to germinate?

Firstly is this true? If this is not true, what’s the process for getting them to germinate? Is this more likely if the Spinosissima is used as the mother?

Many thanks, your friendly novice.

(Do other species roses take two years?)

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Doubt it is an iron clad tenant for the variety and crosses.

l believe that author(s) is probably referring to calendar elapse time experience from start of stratification to first germination for pure cold zone species and near species crosses - as in my case when when switching from first year winter months in fridge stratification (+OC) with no germinations, to summer and a second winter planted in ground and germination noted in second May.

Best l done is 90 days was for 2021 hardies - semi hardies, but seeds not spinos/altaica. Rosa xanthina and gallica Merveille.

Waiting for May this year to see if second batch of 2 winters’ stratification temperatures result in germination (2021 seed harvest - 1st year winter in freezer at -0C, 2nd winter planted in outdoors test bed).

No idea what it takes with spinos …. been a challenge for me for above and just below 0C stratification.

Just ended a cold stratification of 57 trays containing hardy and semi hardy crosses (1000- 1500 seeds 2022 fall) with some spinos.

Removed these Jan 30th, 2023 after 90 days at just below 0C. No germinations so far in 15 days at 15 to 18C. They are in domed growing trays that are moist. Will wait 4 more weeks at room temp, if no germinations then decide if Duds will be put in ground, or freezer again to avoid waiting for nature’s second winter calendar elapse time temperatures.

If you find the magic solution to spino germination for amateurs in 90 days or less, please share it, as l am nearly an octagerian and time is tight.


Well please keep me posted. Would love to see pictures!

Thanks again for the detail you went into. Once I have done some crosses of my own I will return here with my finding, obviously I have a whole season to go through before that can happen!

I used spinos as pollen parents and achenes germinated after ~4 months of stratification. Indeed I read once that if they were used as seed parents, then the germination could take 2 years or even longer. I would suggest to make embryo extractions in that case. It can speed up growing seedlings, although the first bloom may still be a big wait (if the mothers are once–bloomers of course).


I’m my experience it’s a leaky rule/belief. Granted in Australia so climate is likely fairly different to most, may be the fairly wide temperature fluctuations from near freezing to 20c/68f that happens in “winter” causing the difference.

I have an unknown single white spinossima that I collect OP from and just sow outdoors beginning of autumn. There’ll be germinations before spring. Same thing happened with seed collected from a public garden (single cherry and single purple).

Not huge numbers, around a 1/3rd of seed result in seedlings. Could probably do something to increase that but I tend to walk the laziest path as a rule.


I believe roses from Canina group often need 2 winters to germinate (in our climate). You’d have to double the time in the fridge (180 days) for seeds of those types of roses.

I don’t think it is the case with roses from the Spinosissima group.

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While it can’t be well proven I use this:
-Harvest the hips when they are all dark with no green and still FIRM. If collected when mushy I can never break the dormancy.
-Remove the seed immediately and put on a lot of wet toilette paper saturated with a solution of 1 heaping tsp calcium nitrate (mine is pellets not powder) in 4l of water.
-60 days cold treatment
-Germinate in indirect light.
A small trick i have learned is never let the seeds dry out with this section of rose.

If anyone is interested I did find ‘Canary Bird’ seed and I did get Rosa xanthina seedlings to flower.


I am giving boring input to document what l did next this year to encourage germinations from my the major reconn. crossing survey (in my world).

Today back in bar fridge/ freezer for 2nd stratification at a mild temperature of + 2C to + 5C target … after 3 weeks at 15 to18 C …. that followed 90 days at - 4 C to +2 C.

Major change was draining excess water over last 24 hours (peat soil saturated) through quadrupling drainage holes and adding thin layer of vermiculite to encourage sucking water up from lower pearlite and potting soil layer (temporarily raising phraetic surface against gravity? sounds impressive … but may not be correct hydrology science).

Seeds in pearlite middle layer of 1/4 - 1/2 inch thick.

This stage target time 30 days at above zero, then back to room temperature. Or white / green show … what ever comes first.

So after 111 days consisting of ~ 90 days at less than 0C, followed by ~21 days at a cool room temp … there has been “0” germinations.

Not like last year when jigged the Fort Whoop-Up dance due to germinations.


That is discouraging, to say the least.

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Well thank you for your honesty, scared me off them a bit ahaha

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I wouldn’t be discouraged and give-up, but l am infused with “Sisu” vitamins due to heritage.

… the upside is only 20-30% of the parents were F2’s and F1 crossings … with a spino background in crosses, except for a pure altaica cross l tried.

Others succeeded in using and crossing pure and F1 spino / and derivatives. For example RDxS as a pollen parent (at least a half or so explorer roses used RDxS in their line).

Rest are hardy species and crosses with modern semi- hardies. Only thing that is common besides stratification method/technique is one or both parents are stone cold hardy in my garden.

Its a systemic species type and/ or mating harvesting/ prep and/or stratification problem(s). l’ve got to work through because using tenders as both parents is a waste of time for my garden climate

… but zero is zero so far in the path that l arrived at by testing that produced germinations in two separate harvests (aka worked in the past). Now it seems erratically. Like to eliminate burial outside for 2nd winter.

Other variables can-be non viable crosses that can produce duds. But as Johannes says when he wrote “he cant prove” for some aspects that appear to work in his method ( avoid drying out seeds).

Except so far after phase 1 of my just below zero stratification methodology its still zero is zero for 2022 year.

While 2021 was a success (no spino but hardy rose seeds) after single below 0C treatment, and when l put the year before warm stratification duds in the ground for a full summer/winter cycle.

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From my recent experience, I can report that germinations of a cross with Spinosissima hybrids with R.chinensis influence as pollen parent worked in the first year. In addition, the typical Spinosissima character is dominant almost throughout. As might be expected, none of the seedlings flowered in the first year, even though the seed parent is a repeating R.rugosa hybrid. So it remains to be seen if they will flower this year.

Sorry, I forgot to mention my stratification regime:

After harvesting the ripe seeds follows a warm stratification period for 1 month, plugged by 2 - up to max. 3 months cold stratification in the refrigerator at 4 degrees Celsius. After that procedure, the seeds were stored for another two weeks at about 12 degrees Celsius. Most of them germinate already in the fridge or mostly at this stage. The next step for the hard-shelled nutlets is to move them to an even warmer environment at about 18 degrees Celsius. In very hardy cases, I repeat the whole procedure again, limiting each step to one week. So far I have done quite well with this method, no matter what medium for the storage of the seeds is used.


Good to hear Roseus, and use of a china for successful cross is exciting to me.

Below is some success from my path of concentrating on germination first, to see if method works (below zero C) for 2021 season.

The hardy germinated ones in ground for winter - a spinossisima and Bugnet rugosa hybrid Lac la Nonne and R xanthina (x 9).

The photo from today are ones from below zero germination that were brought in for winter after seedlings first summer in ground - l suspect tender.

They are Lillian Gibson (blanda hybrid with HT?) and Merveille whose parents unknown except strong gallica and great color parent, plus rooted cuttings of them that l took in case pollen parent not the same. Note hard water crud deposits of likely ca/ mg carbonates

Also Empress Josephine in there from garden “runner” as not hardy and cant supply replace. In a “ benign” winter will bloom very well.

Another pursuit as to why “agatha” line types sometimes can / cannot turn out to be full hardy in my garden - but not generate seed. Tested her as a pollen parent with L83. No germination so far. I did not use ploidy as a guide for 2022 crossing season.