Do moss seedlings require any special treatment??? I can’t seem to keep mine alive. They all just shrivel up and die as though they are damping off. The ones I’ve got at the moment are open pollinated ‘Henri Martin’. They grow until they are about to make their first leaves and then keel over. None of the others do this. They are in a bed of potting mix with a layer of perlite over the top in an open mini-greenhouse (so basically exposed… just can’t get rained on).
Some seedlings will die off no matter what you do. This seems to be more common in wide crosses but you will also note this tendency with certain parents.
Per HMF I only see one recorded seedling showing ‘Henri Martin’ as seed parent.
Since it’s been around since 1862 it could be there’s a reason why there are so few descendants.
I look at HMF as a statistical tool, among other things.
A number of years ago, I collected open pollinated hips from ‘Henri Martin’ growing in the Birmingham (Alabama) Botanical Garden. I collected hips for two or three years in a row. Germination was good, and I grew several seedlings to their mature size. I don’t recall any particular problems with seedling die-off with these seedlings, for what it’s worth.
Mark
Hi Simon.
What anti-fungal prophylaxis did you undertake in this instance (in the storage and sowing of this seed)?
George
The short answer is I don’t use anything.
The long-winded answer (stop reading here if you have better things to do 
) is that many years ago I would worry about soaking my seeds in fungicides and sterilising the paper towel they were stratified in and using boiled water to moisten the paper towel… and then as I learnt more about the way rose seeds germinate in the wild I started to think that the development of moulds and other such decomposing organisms was an integral part in their germination… weakening the coat of the achene to allow moisture into the seed to help initiate growth of the embryo and leach away germination inhibitors. The weakened achene splits in half more easily allowing the emerging radicle to push through. I’m a big believer in ‘survival of the fittest’ too and think that selection begins the instant I pollinate and from that point I don’t like to interfere with the seeds, seedlings, or plants. If they can’t germinate on their own then they are selected against. If the seeds can’t survive a bit of mould then they are selected against. I also found that my rate of germination was unaffected by dropping the aseptic techniques… in fact it might have even improved and now I have gone from sowing just a handful of seeds per year to over a thousand this year I think my time could be better spent doing other things Then, a few years ago, I started reading Paul Barden’s website. This was a big turning point for me for many reasons. I noted that he used perlite over the top of his seeds and that he believed it acted like a physical barrier against fungi that cause damping off and that since he switched to this technique he had stopped spraying against damping off altogether (is that still true Paul???). Since I have switched to this myself I have also noted a significant drop in the amount of fungal problems. I’m not convinced that these little ‘Henri Martin’ seedlings DID die from damping off… they just died shrugs. None of the others around, of different varieties, did. I’m a senior chemistry/biology/science high school teacher and am in contact with more than my fair share of chemicals already… if I can reduce my exposure to chemicals then that’s got to be a good thing for my long term health.
Simon, I also just use damp paper towels. I no longer use any Captan. Germination is not affected.
Jim Sproul
Simon,
Its true: damping off is no longer an issue for me since I adopted Ralph Moore’s technique of dressing the seed flats with 1/4 to 1/2 inch of perlite after sowing. I use no chemicals on the seed flats whatsoever, there’s no longer any need.
If you have a particular group of seedlings from one specific parent that are dying, I would think this is a genetic flaw manifesting itself. They may be doing you a favor by dying off now, rather than fussing over them for four years and then throwing them away.
Paul
Hi all…
All this makes sense for sure!
I have never bothered with using “aseptic” techniques to be truthful. I am always curious about what others do here. Actually I have not used the perlite either, and I have only had one death out of well over 100 seedlings thus far.
When I examined the seedling, strangely a tight band of residual inner seed coat seemed to have caused a tourniquet-type strangulation at the stem/root junction…I am sure this was the cause of its demise and not pathogens.
George.
I thought there may have been something unique about Moss seedlings that could be the issue… because I have trouble with mosses full-stop! I can never get their cuttings to strike, I have loads of trouble budding them, they set loads of OP hips but they seem to commit hari-keri before developing true leaves or just don’t come up. I can grow them if I buy them struck or budded but as for propagating them… I’m a failure 
Hi Simon.
Which mossed varieties have you tried so far?
George
Cuttings of ‘Dresden Doll’ (about 15 years ago - haven’t seen it since), seed from ‘Henri Martin’, seed from an unknown moss from Highfield House in Tasmania, and buds and cuttings of 'Madame de la R
Simon,
If you currently have any ripe OP hips sitting on any of these moss plants in your garden, I would be more than happy to extract them for you and see whether you get some better results with “embryo culture”. Any success here means one year saved by you!
George
They’ve all been sown or dead-headed off this year thanks George. No biggy though… plenty of other things to occupy my time 