At what temp. range do rose seed germinate the best? Larry popwell
I keep mine in the fridge til at least one germinates and that is 40 degrees and then I take them out and try to put them in a place that is between 50 and 60 degrees seems to work best for me. Do not put them in a place that will get much above 70 degrees because you take a chance on putting them back into dormancy. Thats my story and I’m sticking to it 
. I’m sure you will get varied answers on this one.
Patrick
I’d always read that magical seventy degree F. threshold. I planted this winter, it got hot and they sprang up like winter rye grass! It may depend upon the individual genetics of the plants or other factors, but the warmth, much greater warmth, than I’ve been used to in previous years, stimulated them to jump out of the ground.
I’ve had seeds germinate at 30 degrees and some at 75 degrees. I really believe that humidity contributes to seed germination also. If we get a low pressure weather system coming through with lots of humidity, I put my seed containers outside and sure enough…a week later I will get many germinations.
I’m about finished writing a review of 100 or so papers on germination. There’s no one answer if you think of different species. But for the common, repeat-blooming roses Patrick is just about on target. In a Mediterranean climate, planting outside in Nov gives good germ in spring, whatever that means, say Mar-Apr. Other places, holding at 40 works. In the most recent RHA news I posted stats on a bunch of roses where eventually there was good germ, never taking them out of the frig until sprouted, over a whole year to completion. Some folks find too many losses in transplanting, and it gets tedious when you have to watch over 10,000 seeds. So skill and scale and situation are all important factors. The parentage of the cross is really important to readiness to germ; some are very resistant. And the ripening process in the hip has a big influence too, with too cold conditions lowering germ success a lot.
Thanks everybody …if there are any more lets hear them. All are welcomed… Larry
I live in zone 8B in the Tualatin Valley, which is about 15 miles west of Portland, Oregon. I also germinate seeds on some property in St. Helens, Oregon, which can get colder and windier since it sits next to the Columbia River. Both areas are planted outside around late October within a soil-less media blend. Germinations always begin in mid-February (already have some!) and continue throughout June. The peak is obviously in April and May. I seem to have better germinations with this method than various indoor methods I have tried. I am guessing because of several things – 1. the consistently moist climate. 2. fluctuations in temperature. 3. fluctuations in light 4. passing through the dormant season. 5. being subject to naturally occurring microbes.
For what it is worth to anyone looking at economic ways to germinate seeds (since light bills can get expensive indoors!!!), the outdoor method is highly cost-effective.
So, I am unsure if this is helpful, but my answer to the original question would be that I am sure an optimal germination temperature could be found, but that I find that a ton of dynamics are at play regarding germination, so I am unsure if an exact static temperature can be stated since germination can be so dynamic.
Here french Riviera in a very airy plastic tunnel germinations are beginning right now as night temps are rising above 5
Jadae…Some real interesting stuff … our zone being nearly the same… any more info… ALL is appreciated…Larry Popwell
Hi Larry,
It does depend on the rose, but in my experience seeds germinate best when the temperatures are ranging between 35 and 65. Remember that if a rose seed has not reached its cold stratification requirement, the seeds will not germinate no matter what the temperature.
After years of getting poor germination, I now leave my rose seeds in the refrigerator until I get at least a few germinations in the baggies. Almost every variety will get germination in the refrigerator once that cold stratification requirement has been met. After about 3 months, if nothing has germinated in the fridge, I will take the seeds out for a week at 60 degrees. If nothing germinates during that time they go back in the fridge for a few weeks. I keep up that cycle until see germination in the bags. Patience definitely pays off. Jumping the gun and planting seeds in warmer soil early just leads to frustration.
Hope that helps.
Shane
Shane… Thank you very much… it sure does …what growing zone r u in i’m in 8a… sometimes it looks like im in 7b…Larry popwell
I am convinced that germination times and temps are variable between various rose varieties. This is true too, of number of days needed for hips to mature. Some rose hips mature very early, while others mature very late. This is what we also see with various fruiting trees. With apples for example, there is a tremendous variation in period to ripening of the fruit.
Some of my seed parents if left in the refrigerator longer than 8 weeks will start germinating into a very large mess, while others won’t germinate if left in the refrigerator for 10 weeks, but do after being put into the natural fluctuating temps of early Spring. Since I prefer planting my seeds into seedling benches before germination, I only keep them in the refrigerator for about 6 weeks. After planting, some varieties germinate immediately, while others take several weeks, and then germinate well. In my 2010 Seedling Database mentioned in another thread, it can be seen that ‘Pearl Sanford’ germinates fast and early, while I49-2 germinates well, but later (the columns on the left are weekly germination counts with the date counted at the top of the page). Pollen parents also have an effect on germination times. As has been mentioned, yellow pollen parents tend to delay germination in otherwise faster germinating seed parents. I have noticed this year that ‘Black Magic’ seems to also delay germination when used as a pollen parent.
Most roses are “mutts” with quite a range of variation in many of their characteristics, including germination temperature.
Jim Sproul
Thanks Jim… Good to hear from you…That is my belief too… quit a bit of varations… Larry Popwell