How long do you keep ungerminated seedlings for?

I read that Ralph S.Moore used to hold onto seedlings for up to 7 years to see if they would germinate. How long do you cling to hope and have you heard of any other famous rosarians doing similar lengths of time?

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If you mean germination wait, l read the European Rose Hybridizing FB group post on stratification time to germination and Ralph Moore experience (reply by B Weeks on her R glauca work was very interesting as were others).

And very applicable to my short experience file that it can at be more than one brief and sometimes multiple years of stratifications / burial before germination - may depend strongly on rose type, F/M parents versus natural location of dominate parent type (according to speculation and inputs).

They aren’t wrong in my limited experience for my hardy to very hardy crosses (some have one tender parent in crosses). Have now two batches tried, one nearly two years ( one fridge winter below zero C and one natural winter).

After second winter stratification / soul burial in garden, hardy seed parents germinated. Except for spinossissima cross all were semi hardy very hardy ops.

Second set duds going through second natural winter.

So as to your for your question yes l am up to two cycles over two years for same seed in growing media.

See many more 1st stratification duds in my future and now view planting duds in garden for a second natural stratification as planting winter wheat crop for spring.

Don’t know personally any famous commercial hybridizers though did meet Peter Beales and score an autograph on his last book.


I had asked Mr. Moore once what he felt about holding on to seeds past the first season and he said would hold on to unusual things for longer periods but he generally didn’t hold seeds from “usual crosses” more than one season. He stated many times he observed that those which germinated the first season tended to be more of the repeat flowering types he was after. Those which germinated the second and later seasons tended to be more once flowering types. He was primarily interested in dwarf, bushy, continuous flowering roses and felt those were most likely to come from faster germinating seeds. I have held on to very few seeds after the first season and never found anything sufficiently interesting to me to retain very long. The longest I have ever retained a seedling which hadn’t flowered was seven years. When it finally flowered, it wasn’t worth the water nor room so it became “mulch”.


I wonder if anybody can recommend long term storage conditions for those ungerminated seeds? Right now, my germination rate for 2022 crosses has slowed dramatically, and if 2021 is a guide, I will see no more new seedlings this season. Last year, I threw out all remaining seeds after about July.

If I do want to store, under what conditions should I do so? Should I keep them continually moist and at room temperature? (I would think mold would take a pretty heavy toll) Or is it OK to re-dry them, and refrigerate? Or something else? Is re-stratification a good idea? When?

I often see discussion about how long to keep them, but rarely any specifics concerning actual conditions…thanks.


In 2021, the President de Seze rose berries were left on the bush during the winter of 2021-2022. In early February 2022, after being brought in from the field, they were sown immediately and germinated very quickly, the seedlings being very strong. Stratification took place over two winters on the bush. During the winter there are frosts of 15 degrees or more.


Interesting thread.

Does anyone have a small area in the garden where they throw their ungerminated seeds? Where you could maybe find some surprise seedlings once in a while?

Anyone had nice surprises this way?

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With the seeds that took two years to germinate: I took them out of the cold storage when my other seeds were done germinating for the year (usually early May).
I kept them at room temperature for a while (a couple of months maybe). I keep them in moist paper towels, so I just changed them to a new towel if it stared to mold. I then put it back in cold storage where they remained until they started germinating in late winter, about the same time as all of that years seeds.
I haven’t done this with many, just a few species crosses, but it worked well.


Might be time to formally consider adding annotates or addendum(s) to the status quo formal stratification and germination derived method “handbook option” on RHA site.

Caveat option, since no formal science vetted belief in it, as an alternative such as all else fails try this but “YMMV for stubborn, cold to very cold zone rose crosses /seeds”.

“Climate of Species Origin Optional Methods” aka last resort options, to get germinations after first stratification and germinations period over - very green method.

Wish l had been stumbled across options of “Time and Temperature and Stratification Cycles” 10 years sooner as a hand book.

Praise for the tin can of seeds in a snow bank in zone 3 in mid 20th century, and Wisely tests, to get rid of don’t freeze mind set for ice rose bushes seeds in my mind.

Thanks, everyone. Right now, all my 2022 crosses were refrigerator stratified 8 weeks in Nov and Dec, and subsequently stored at a variable ca. 45 - 65F in my attached but unheated garage. The first 4~5 weeks after removal from the refrigerator had about 30-40% germination, and has slowed since to now none for about three weeks.

I suppose my plan for the ungerminated remainder will be to keep seeds moist at room temperature until the fall, and then re-stratify with my 2023 crosses, rinse and repeat. Would anybody advise against that approach?

I would agree to this plan as I do it in the same way. Nevertheless, it is advisable to carry out a brief check every 8 weeks, as spontaneous germination may occur, in my experience especially in July and August.Of course, the probability also depends on the type of crossing.


Agree and good luck. Worked for me and continue with multiple batching with ice rose seeds.

Your’s l believe are warmer variety. Should work or odds in your favour.

My 1st stratification of 2022 season harvest l am mind battling Darth Germinator (Arnie character role relative) as ice rose seeds were below 0C. Went in for second 2-4C strat.

I never saved seed trays after the first year. Occasionally a few seeds would germinate in October, once the weather had cooled down. But I always dumped out the trays by December to ready them for the next year.