Because of generally decent price and constant availability, i normally use Miracle Grow Seed starting mix. After i used up most of the Miracle Grow i bought a bag of Pro Mix potting soil and continued seeding. The Pro Mix seedlings look very different than the MG seedlings.
This is two seedlings of Ancient Sweet peppers growing in Pro Mix
And these are Snapper sweet peppers and Raveena eggplant growing in MG
Also, my tomato seedlings have also had a purple tinge to the underside of their leaves when grown in MG, though MG SS mix claims to have extra nitrogen in it. I can't seem to get that color to show up well in pictures.
Now the eggplant and peppers in the peat pots... it could have something to do with that and the fact that the Ancients are in a paper tray, but its pretty drastic for that to make such a difference.
So, even though the Pro Mix was not labeled for seed starting ( i forget the exact product, but i'll remember the packaging for next year) i'll be using it next year instead of the MG. I sterilize it anyway when i wet the soil in a bucket.
No more Miracle Grow.