Growing rose from seed (for Carole)

Moved from another thread to give it its own thread:

After seeing Bemo's seedlings from Bonica and how different they can be from the parent plant I have refrained from deadheading my roses so they can form hips. Today I removed two hips from "Marijke Coopman"and extracted 28 large seeds and a few small ones which probably are to small to be viable. Can anyone tell me why put them in the 'fridge ? Although we have put some rugosa seeds in the 'fridge some in paper towel and some in vermiculite - both in plasic bags - just to try it. I cannot understand why they would germinate in the cold. I have a heated propergation bench with auto' misting and a range of propergating materials e.g. perlite, vermiculite, sand and fine potting mix. Any advice would be appreciated as before we just put the seeds into potting mix and hoped for the best. Carole.

Rose seeds require stratification to break the dormancy of the seed and to weaken the seed coat to allow germination. Germination inhibitors are produced by the seed to prevent it from germinating at the wrong time of the year. Germinating in the middle of a harsh zone 4 or 5 winter would inevitably kill the seedling so preventing germination until conditions are more suitable helps to maximise the chances of the seedling surviving. These germination inhibitors leach out of the seed during the stratification process and when levels are reduced to a critical point germination can then proceed. During this period of stratification moulds and other decomposing organisms help reduce the structural integrity of the seed coat allowing the two halves to come apart or weaken to allow the emerging root and shoot to do so more easily and to allow moisture into the seed (achene). Some research has shown that if you take seeds just before they are fully ripe you can actually avoid the dormancy period allowing you to sow them straight away without stratification. Some rose seeds don't seem to require cold stratification and will germinate after a few weeks of warm stratification only. Others like to have warm stratification followed by cold stratification. Most, however, require cold stratification. When you notice the seeds beginning to germinate in the fridge what has happened is the germination inhibitor (abscisic acid) has leached out to the point where germination can now begin and the temperatures in the fridge are not sufficiently low enough to stop growth altogether. I have decided this year to not allow the seeds to germinate in the fridge. I'm going to give them 8 weeks in the fridge and then I'm going to sow them all. Rugosa seeds have germinated very easily for me in the past and were always the first to germinate in the fridge. Don't count the small seeds out. Because they are smaller the abscisic acid can leach out more easily resulting in easier germination. It's the big chucnky seeds that can be more difficult to germinate.

Mmmm, now that gives me something to think about overnight, I will check to see how close the other hips of Marijke Koopman are, because she has huge flowers I would like to see what her offspring will be like.I may try the seeds both in the 'fridge and out. Thanks for the help. Carole.

Thanks for this information Simon. We are lucky to have you !

I am not sure if this is the thread I was posting on but my seedlings are growing slowly but surely. C. Marlow is going well but the 2 rootstocks are not looking well and are not thrivng but I will continue to look after them and hope.

My rootstocks don't look good at this time of the year either... might just need spring to bring it out of them... keep me posted though... I've got loads of struck cuttings you can have.

Any photos of your seedlings?

Thank you, I am so glad Christopher Marlow is going well.