Help with a seed-starting mix.

[AaronR]

Hey friends,

Alright so I've read a ton of threads now on the subject of mix and would like a bit of tailored advice for my own attempt, if you don't mind.


I have sourced an Oil-Dry product that is the Canadian version of NAPA's. Calcined DE <1% Silica, MSDS is identical to NAPA's.

I also found Chicken Grit/ pebbles.

So what else do I put in there? Just a bit of course sand? I have some Pro-Mix Seed starting mix I use for capsicums... I read top soil somewhere. Or earthworm castings even? I even read somewhere to just start them in a regular seed-starting mix and move them to a mineral mix AFTER they come out the bags (which may be what has me a bit confused...?)

If I stick with just coarse sand/oil-dry/chicken grit do I need to add a fert.? -- I picked up some of the schultz cactus 2-7-7 but am weary to use that now after reading discussions on the amonia N content etc etc.. Can't get the popular dyna 7-7-7 here unfortunately.

An X parts Oil-Dry X parts Grit and X parts whatever else would be incredibly helpful to this rookie.

Just want to get a game-plan before I go out spending mula or worse killing seedlings.

Thanks a ton, I know it's an overly-discussed newbie question and all.

Side-note - I intend to keep them bagged up as long as possible.

[Ivan C]

I use straight sifted NAPA. I haven't found a soil I am satisfied to add to it. I find that I can spray the seedlings with Hydrogen Peroxide 3% to kill off any algae that I encounter after removing from the baggies. If soil is added then the organics bubble up and just create a mess. I would also leave out the poultry grit since it is probably marble and is quite heavy. All it does is sink to the bottom and has no benefit to the seeds/seedlings. If you think you need it for weight, then add it.

[AaronR]

I use straight sifted NAPA. I haven't found a soil I am satisfied to add to it. I find that I can spray the seedlings with Hydrogen Peroxide 3% to kill off any algae that I encounter after removing from the baggies. If soil is added then the organics bubble up and just create a mess. I would also leave out the poultry grit since it is probably marble and is quite heavy. All it does is sink to the bottom and has no benefit to the seeds/seedlings. If you think you need it for weight, then add it.

Thank you for the response Ivan!

Ok, so if I were to use straight up NAPA, how would the seedlings get nutrition? Like I said I would like to leave them sealed in their baggies for up to a year depending on the genus. Surely they would not thrive in an environment that is completely inert?

[iann]

You feed with a dilute soluble fertiliser. Often, preferably every time you water. Not really suitable for vigorous growers, but can work for slow species.

[AaronR]

You feed with a dilute soluble fertiliser. Often, preferably every time you water. Not really suitable for vigorous growers, but can work for slow species.

Alright, I can do that. Thanks for responding, Ian.

So in that case, would I use a diluted fert In the baggy itself? This is where I'm a bit stumped..

[Ivan C]

I don't leave the seedlings bagged up too long so I don't fertilize till I start the watering/drying cycle. But this year I plan on experimenting by adding fertilizer to the rainwater that I sterilize for the seeds. I don't know if microwaving the fertilized water will neutralize some of the benefits but it's worth a try.