Sounds great. I'd substitute coir for the peat moss and add a touch of nitrogen.

For seed starting? 2/3 Peat, 1/3 vermiculite or perlite, and a little lime to balance the pH. Same as the good commercial seed starting mixes, maybe a little wetting agent. Then for growing-on mix you could add all the other stuff if you wanted. I'd just add some compost or use compost tea and skip the rest.

How many plants are we talking about? Not sure that it would be less expensive than just grabbing a bag of a good commercial mix. For the average home gardener a bag of something like Jiffy Mix or Ferry-Morse Organic Mix at $4-5 is usually enough unless you were doing hundreds of plants.

Dave

Sifted aged home made compost and vermiculite 50/50. I added a bit of vermicompost to mine as well 40/40/10.

None of the above. I will continue to buy a bag or few of Jiffy seed starter mix for $3.50 each and plant away.

Concocting a seed starter mix is on my "life's too short" list. Jiffy works too well to bother.

I put my own together this year and probably wont ever again. Light Warrior from Fox Farms is great stuff and I wont go without it again.

Damon

You can safely miss out the bonemeal as it will not have sufficient time to break down into usable material for the seedlings before they have to be transplanted, a better choice would be powdered superphosphate or granuals that are available to the seedling roots straight away.
Also as Bill says-( Coir) fibre is very good as it has a very good drainage and stops a lot of seedling diseases from developing on the surface of the mix-plus it is light and airy.

Last year I did something like 16,000 seedlings of various flowers. Everything from sunflowers down to teensy tiny trichillium seeds. (I work on a flower farm)The only thing we use for seed starting is a simple mix of equal parts vermiculite, perlite, and peat moss (sphagnum). They do great. It does take a bit more mixing to get the moss to properly "wet" but it's just a few swipes of extra mixing. We don't usually feed the seedlings until they have at least a pair of true leaves, mostly two pairs. Until they have the real leaves they're getting their nourishment from the seed leaves anyways. Once they've been transplanted we add in some compost to the three way mix and water every so often with fish emulsion.

I use only Pro=Mix or Fafard or Jiffy Mix for starting seed.

For starting seed you don't need all that much and since the initial transplant is at the 1-2 true leaf stage and since the seedlings are only in the artificial mix for a couple of weeks I can't see adding anything else at that time that would be beneficial.

The initial energy for seeds to germinate comes from the endosperm of the seed and then the cotyledons help and once the true leaves appear photosynthesis takes over to create energy for further growth.

It's perhaps a different story for some once the seedlings are transplanted, in my case to cells, 2 X 2 inch, 32 in the insert that goes into a standard nursery size tray.

Carolyn

Does anyone know where I can get the JIFFY seed starting mix in commercial quantities????
I think this stuff is great, the vermiculite is very fine and works perfect for even the tiniest cell packs (72 for me). I will eventually make my own as we are doing "hundreds" but at Walmart $4 for 10 qts seems pretty cheap and it's labeled "organic" now which is great because I'd like to market Organic Seedlings in the future. I need a bunch of this! If I do my own with some Vermiculite, Perlite, Coir etc.....how do I get the Verm to such a find grind? I agree life's too short to be sifting straining and grinding this stuff. Any help for a gardener with a back problem would be appreciated.
Thanks!!

You should be able to visit a nursery supply store and get what you need in various grades. In some cases garden centers/nurseries with great customer service will order some for you and pass on a modest charge. Works well if buying less than a pallet of each.

Having said that I have never understood why mixes designated 'seed starting' use super fine particles. For my own seed starting I use the same thing I grow them out in which is a pine bark based mix. There is nothing fine about the particles and I have had no issues with the particle size being larger.

This mix has no peat or vermiculite in it.

Frankly, one doesn't even require a mix to germinate. Wrap a moist paper towel around the seeds, put in a plastic bag to conserve the moisture and the seeds will germinate.

With the relatively coarse mix I use I have germinated very small seeds such as petunias with no issues. I mention that because I think some are concerned that seeds might fall 'between the crack' and go too deep. Haven't had that problem, but then again I bottom water.

So it sounds like perlite, vermiculite and peat moss is the best mix for starting- makes sense.

How about a soil mix for the later stages of potting up? Does my original suggestion sound good for that or do y'all think it's unnecessarily complicated? Any alternative suggestions?

Also wondering if anyone has an opinion on whether mycorrhyzal treatment is effective in getting healthier plants and eventually higher yield.

Thanks!