I've been using seed starter for about ten years with my tomatoes and peppers.

Use the 'Search' feature to check pasts forum threads on potting mixes. And read amy FAQ short articles that might apply.

There were 247 hits on threads using the Search feature for 'potting mix'. Just in this forum. Searching all the forum areas will produce even more hits.

I think my question was poorly worded. My second paragraph confused the issue.

I was looking to spark a discussion on alternatives to purchasing seed starter mix. Every search I've found turns up references to store bought vermiculite, perlite, peat moss, and stuff like that. Since the folks on this forum seem very resourceful in turning just about anything into compost, I was hoping that I'd have similar luck in creating some sort of good germination medium without always running to Home Depot and picking up plastic bags with bar codes. For some reason I just don't feel all that "sustainable" when standing in the check out line. I'd love to make my own. I'll keep searching.

Elbourne-

You're my type of gardener. I've been on the same search as you & it is difficult because of the current conditioning of most gardeners.

After digging up some failed veggies I decided against a mix of 50% top soil & 50% compost. Reason being I had some cucumbers with nematode nodes on the roots. Otherwise, I would've used that for seed starter.

Then I started looking for home made seed starter until my compost piles break down & can get the bacteria levels under control.

From what I've read the soil under the leaves will be quality stuff. Try to half that with some soil & report back to us.

It's all trial & error anyway. I'm sure there will be people who think sterile seed starter is the only way. But I've read about plenty of people who have never encountered a problem using unsterile seed starter.

Hope this helps.

Roots are the heart of the plant, and should always be your first consideration, especially when it comes to healthy seedlings. Seedlings want and need a LOT of air in the root zone. If they don't get the air they need, anaerobic fungi multiply quickly, dashing hopes and spoiling all the fun.

Any combination of topsoil and compost is a poor choice - even if you go to the effort of sterilizing both components. Compost on its own is extremely water-retentive, so would require very judicious watering habits to avoid compaction and saturation. The problem would be substantially compounded by adding topsoil to compost.

If you're going to make your own seed starting mix, I would suggest a large fraction of pine bark fines, and smaller fractions of peat and perlite. The pine bark fines + perlite are larger particles and ensure a degree of aeration that any combination of smaller particles like compost/ peat/ coir/ topsoil/ sand cannot. You can then add enough peat (less than 15% of the total mix) to adjust your water retention so the medium doesn't dry too quickly. Pine bark is less likely to be infected with the volume of soil-born fungal pathogens that cause damping off than compost, perlite is sterile, and peat, because of its very low pH, can almost be considered sterile.

Seeds don't need nutrients to germinate, so focus on the seed starting medium's STRUCTURE, because that is what will hold greatest sway over the health of the seedlings (unless light & temperature is particularly unfavorable). You can always fertilize about the time the first true leaves appear.

Al

So Al, are you suggesting to simply use 5-1-1 as a seed starter mix?

I do it all the time ..... gritty mix, too. Commercially prepared seed starting media are usually steam sterilized, but are also usually some combination of peat & vermiculite, which makes them excessively water-retentive. My experience has been that the saving grace of the additional aeration trumps the likelihood of incurring infection by the fungaluglies that thrive in the anaerobic conditions that prevail in soggy media.

I think that as the minimum standard, in order for a container soil to be considered 'GOOD', you should be able to water correctly w/o concern for root rot when you DO. You should be able to fully saturate the soil and flush it of accumulating salts without worry when you water. If you can't do that, how can you call a soil 'good', or even suitable?

Al

Al, I thought you used finer particles for starting seeds? I thought I'd read that you use turface, bark, and perlite that you'd screened out using an insect screen. That would make sense for very tiny seeds that need to sit on top of the soil for germination. Is that correct?