Rose Hybridizers Association Forum

This question probably comes every year, or some related question. I've browsed earlier topics but haven't found satisfying answers.

I've been stratisfying my roseseeds in my refrigirator in ziplock bags with paper towels. I've used a bit of bleach to reduce mold last year. Soked the seeds also in diluted bleach. I had similar germination as other years en more mold :)

I saw some references to two types of easy stratification. And me, being a busy person, like easy.
1. You can simply put your seeds in water for a month in the refrigirator and that would give good results. Is this a tested method?
2. Or you can simply put the seeds in a ziplock bag with very little misting of water.

I would soak my seeds in water for two days (maybe with some diluted hydroperoxide (0.5% or so) and then put them in ziplock bags. Without any medium. A little mist with water and a little hydroperoxide. Just to prevent mold.

Now I have about 8% germination. I'd like to do a bit better :)

Does someone have experience in no-medium cold stratification?

I haven't tried it too much, but when I have, I have been disappointed and went back to peat. When I don't use medium and use a bit of moisture in the bag, there often is some fungus that grows kind of sticking neighboring seeds to each other and then the seeds getting a bit dark/grey/brown and then rot. Paper towel is okay, but I struggle with the root hairs getting into it and a challenge to pull the seedlings out to transplant. Peat is loose enough to get them out and a wonderful spongy buffer at the right moisture to give the seeds some air and good moisture availability. It seems to suppress some of the worse kinds of mold it seems from its partial antifungal properties. It is also easy to see the white roots against the darker peat in the baggies compared to sand or vermiculite. For me having a substrate to buffer moisture content around the seeds has been important so they aren't overly wet in the baggies or too dry.

I went with peat in ziplock bags :) They're in the refrigerator. I've cleaned them with the hydroperoxide solution that was suggested in "Simple Embryo Culture for Plant Breeders" by mr. Holeman and also left them rehydrate over night in that same "Solution A". Rinsed them with clean water and put them in the bags with some moist peat.

I hope to have much less mold than other years. Fingers crossed.

Hey thinking about your description and germination rate, The reference manual for woody plant propagation mentions that hybrid roses can have a germination rate of 10-30%. You might need to scarify with acid or warm stratify for a few months to improve germination. For the length of peroxide soak maybe usually I'll just do a short soak then rinse - but also stratifying in damp sand vs peat makes an improvement for mold. Some seeds if I'm seeding mold I'll just do a peroxide rinse before they're done germinating and change the bag etc put them back in the fridge.