Can any Australians here suggest a soil-less media product I can purchase locally which might be compatible with rose seedlings?
If you cannot make a perlite + vermiulative mixture, then the next best thing could be perlite + hydrocrystals.
I see…I was thinking to do a perlite/peat moss mixture 50/50… Is that also ok?
That is fairly standard. Peat is not completely neutral (it softens hardness, and cans ometimes lower pH by tiny fractions) but it is fairly close. Coconut coir is pretty much the same, except that it can have salts + hardening factors. Its because of the bogs vs. the oceans, and how they affect the mediums. The major difference, though, is that coconut coir doesnt attract pests. I have always considered ways to get Neem oil into perlite + peat mixes to eliminate pest + damp off issues, but it seems like too much work for a lackluster payoff.
BTW, DO NOT BUY MIRACLE GROW PERLITE OR PEAT GERMINATING SEEDLINGS. I am writing that in caps because those stupid jack##### put fertilizer in anything and everything they touch. However appealing, it can kill rose seedlings as they germinate.
Thanks, I’ll do the peat:perlite thing 1:1.
There are horror reports of some vermiculite products manufactured from last century being contaminated with asbestos.
Even though contemporary vermiculite products are supposedly quality checked for purity and absence of asbestos these days, and hence asbestos is no longer an issue, I prefer to stick to perlite, silly as this may seem!
Its safe in America now that they know the different sources and how they work/where they are, but I have no idea for Australia.
Perlite and Vermiculite have vastly different uses. Vermiculite absorbs water and nutrients. Perlite drains and aerates.
In a 1:1 perlite : peat moss mix, is there any need to keep a constant bottom tray of water, or will this media hold water on its own if watered say once daily from above (assume 60-90F temp range, and 60%+ relative humdity)?
Jadae,
Is the p/v mixture 50/50?
Thanks,
Jim
“ish” I mix by eye – just like I cook 
Its roughly 50/50, but I recommend putting your hands through it after it is wet to see if it seems right.
This may not be relevant for Australia, but I wonder if anyone here has had any experience using Turface in their mediums. Over the past several months there have been many conversations on the Container Gardening site of GardenWeb about using Turface in their soilless mixes. Apparently it has gained a lot of respect, being used in a mix of 1 part silica sand, 1 part Turface, 1 part fir bark fines.
I can’t tell you myself that “Eureka it works”, but it might be worthwhile for you to research as a possibility.
Susan
Heat Treated Montmorillonite Clay Mineral – AKA Turface.
"Crystalline Silica (Quartz) [EPA Hazard Category: Health]
Carcinogen: OSHA - No NTP - Yes (respirable) IARC - Yes
This product contains up to 5% crystalline silica. The International Agency for Research on Cancer (IARC) has stated that
there is sufficient evidence of carcinogenicity of crystalline silica to human beings. It was noted that carcinogenicity was not
detected in all industrial circumstances studied. The NTP’s Sixth Annual Report on Carcinogens include respirable crystalline
silica. The Hazard Communication Standard (29CFR 1910.1200) requires that any material containing over 0.1% of a
substance reported as a carcinogen in an IARC monograph or the most recent NTP Annual Report on Carcinogens must be
identified as a carcinogen. These identifications are for hazard communications only and do not serve as assessments of
carcinogenic risk. Crystalline silica is known to cause silicosis. At dust levels below the recommended PEL exposure to the
crystalline silica contained in this product should not present a health hazard."
"Chemically it is hydrated sodium calcium aluminium magnesium silicate hydroxide (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2
I like your idea of perlite + hydrocrystals.
Will check these crystals out this afternoon if I get the time for shopping!
Theyre cheap as sin. 1 small baggy (4 bucks US $) is like 21 gallon pots worth of cubic size. The only major con to them is that they degrade by year 2, which is hastened by extreme dry heat (like Robert’s area). Fair warning, though – it is easy to overdo hydrocrystals. Be careful with the ratios, and only mix after the crystals are full-sized pieces of gel.
I am currently using a mix of 2/3rds perlite and 1/3rd hydrocrystals inside a terrarium bell to grow out an own-root seedling. I am unsure of what seedlings would like, but do be careful on proportions because hydrocrystals work REALLY well.
I am very temtped to try perlite+hydrocrystal instead of the perlite+peat (especially for my current embryo cultures) for all the reasons you cite.
If it fails, I only have myslef to blame. Anyways it is fun learning as you go!
Thanks for the extra advice on the correct application and ratios!
Re the Turface, thanks Jadae for checking the MDSD. For some reason I had not done that. I always do when researching products for the household or for the chickens, but for some reason this slipped right by me. I do have a 50# sack which I will probably use, but I will do rather a bit more research on it’s carcinogenic possibilities before suggesting it again…
Susan (with a bit of egg on her face)
Henry’s comment on another thread reminded me that pet stores sell colored sand for reptiles. Further, they also sell dark-toned natural sand, too. However, sand is mostly silica, hence its ability to absorb. Its also dense, hences its water-immune nature. That might be an issue for such delicate critters as embryos. I dont know though.
I think I 've solved my problems with poor color contrast to do with sowing white embryos sown against whitish media…just sow one embryo to a small pot containing whitish media, then there is no issue about uneven sowing distribution!!! LOL
Yeah, I think sand will be too dense and potentially too drying for embryo work?? …also, I may have gotten lucky and solved my media for embryo germinations work in WEC, in that your perlite+hydrocrystals suggestion seems to be the shot!!
1 part pre-wetted hydrocrystal added to 10 parts (ordinary coarseness) perlite seemed to give an appropriate media for WEC-embryo germination work. We shall see!!!
I hope it works. Its weird stuff, lol.