How long in cooler

After reading many articles about the length of time seeds should stay in cooler I am just a little confused which is better then very confused I guess. Some say 6 weeks, some say until they sprout,some plant them in the cooler,some plant them all at a specfic time of year(usualy in Dec. in my neck of the woods) and then there or those that sometimes even plant them the following year. I know everybody has diffent thoughts on this and they may all be correct but I would like to know if their are any guide lines that I might try. I have started harvesting hip for about 3 weeks now.

Thanks

Mo

Hi John:

Looks like you’ve got the spectrum down! I’d agree that any of the above can be met with success.

What I do:

  1. Harvest hips and store hips in labeled ziplock bags in frig.

  2. When all hips have been harvested (and I get around to it), the seeds are extracted and placed in damp paper towels. I used to use a solution of Captan to dampen the paper towels, but last year just used plain water which worked about as well as with Captan.

  3. Store seeds in paper towels back in labeled ziplock bags for 6 to 10 weeks (or longer is fine, but you will start getting germinations in the frig). I like to plant my seeds if possible before they germinate into my seedling beds.

  4. After chilling period, I plant seeds directly into seedling beds. Before my greenhouse, I followed the same as above, but planted seeds in flats where they germinated and then I transplanted them into pots while still at the “seed leaf” stage.

There are many ways to do the job and I am sure that some varieties will give you better germination with one method while other varieties would prefer a different one.

Try a couple of different methods and see what works for you. Good luck!

Jim Sproul

Mo, I don’t have the room for flats, so if you don’t have much space like me, and you have a lot of seeds, you can do as Jim suggested, but instead of planting all seeds in flats at once, you can wait until each germinates and pot only the germinating seedling up at that time. As Jim said, some will begin germinating in the fridge, but if you remove them all from the fridge after 8-10 weeks or so, you will get faster germinations. The downside to this method is if you don’t use captan, the seeds may get very moldy after being out of the fridge for a while. I check on them and clean them off about once a week and change the paper if the mold is getting out of hand. As a first line of defense, the moldy seeds can be soaked in Hydrogen Peroxide for 24 hours which often works well, but if that doesn’t work, a stronger treatment is 1/8 teaspoon of Oxyclean to 1/2-1 oz of water which I have found works on more types (but not all types)of mold.

That’s a great question and one that seems to rely a lot on the germplasm. There are a number of older papers looking at the dormancy of various rose species and there is great variation among species. For instance, R. rugosa has a long dormancy and need a longer duration of cold to overcome it (they need ~12 weeks) and roses in the Synstylae section like R. multiflora and R. setigera have a relatively short dormancy period (~6 weeks seems to do the trick). With modern roses being such a mixed up lot, duration of cold is probably variable and a shorter cold requirement probably has been indirectly selected for over the years by breeders. Some other tips that I’ve experienced or heard from others are:

-Remove the seeds as soon as possible after the hip is ripe so germination inhibitors do not continue to move to the seed so you will have less dormancy to overcome.

-Keeping the seeds in the fridge and transplanting out seems to keep germination going because if ones warms them up there will be a big flush of germination, but many seeds that are later at accumulating the cold required go into secondary dormancy and need to start accumulating cold all over again.

David

Hi John,

I think it is important to repeat something that Jim said…all of these methods can give you success. I think it is really just a matter of finding what is comfortable for you, and what works well for you. There isn’t necessarily one of these choices that is wrong, or one that is more right…so I wouldn’t worry to much about choosing the “wrong” one when you give it a try.

As for me…I do something kinda convoluted a bit with the “cool” period, and probably way more complicated than it needs to be…but this is what I do;

  1. Clean the seeds right after harvest (I’m impatient and ready to get them into storage right away so that they will germinate sooner…so hence, I happen to remove the seeds right away…again, don’t think this is necessarily the absolute “right” way…just my choice).

  2. I will soak my seeds in hydrogen peroxide from any where between 12 and 24 hours, just depends on when I get back to them. I do this in attempt to control mold “stuff” later on.

  3. I store my seeds in a soilless potting mix held in petri dishes, with a label across the top.

  4. I stack the petri dishes in the fridge for 8 weeks. I keep an eye on them though fairly regularly just to see if anything started to germinate.

  5. I then take them out of the fridge and set them in our guest bedroom for about a week. That room is closed off from the rest of the house in the winter and has temps that fluctuate between 50 and 60 degrees during the winter months…sort of my little attempt to imitate natural fluctuating temperatures of spring.

  6. If nothing germinates I put them back in the fridge for another 4 weeks, again keeping an eye on them for germinations. They come out for another week in the guest bedroom. If nothing is happening still…they go back in for one final period of 4 weeks in the fridge. After that I bring them out and just leave them out. But, last year by this final period in the fridge I had something happening with all of my seeds by this point.

Like Judy, I plant my seedlings one at a time as they germinate in their containers. I don’t have a greenhouse yet…just growing racks and lights set up in my basement. So that works better for me. Again, I think it is really just a matter of what your situation is and what works best for you.

Thanks all for the infomation. For the few years I have been trying this I remove the seeds from the hips when I harvest them and use a captan soak. My problem is if they germinate to soon I don’t think they would make it in the heat. I have mixed results with planting them all in December but it may be other factors involved. I will keep playing. Ain’t it fun?

Mo

I remove the seeds from the hip and put then in the plastic bag in the fridge (water, no fungicide) as soon as they are ripe.

For the crosses I’ve worked with so far (all rugosa crosses) I’ve never had germination in the fridge. Somewhere between 12 and 16 weeks later I plant the seeds and they start germinating.