My 4 inch transplant pots will be here this weekend, and the seedlings in the 72-cell flats are just (mostly) about ready to pot up, but I'm still undecided/unsure about what medium is best to re-pot them in until they're ready to go in the raised beds (other than "soil-less"). I need to make a decision p.d.q. at this point. (OT- Been dragging my feet due to weather. Can you even believe it's snowing AGAIN this morning? Argh! DH and the kids are off *again* today! I love em to death, but I was *so* looking forward to the peace and quiet after last week's weather-and-SB-related insanity here in Dallas *whine*)

Over the course of this planting season I'll be growing tomatoes, peppers, some flowers, cucumbers, pumpkins, melons, herbs, etc.

I'm guessing it'd be more economical to mix my own? If I go that route, what (if any) amendments could/should I add that wouldn't be too much for the young plants? If I added just some worm castings, would that be enough, or will I need to fertilize further before they go in the ground? I've only used organic amendments/fertilizers up to this point in my beds, but have no idea about seedlings. (New to gardening as of last spring and I did all purchased transplants last year.)

I was looking at pre-bagged soil-less mixes from a few local shops to compare, (not MG or the like, more like Roots Organics or Happy Frog) and their mixes list stuff like bat guano, kelp, alfalfa, etc. in addition to worm castings. Would I notice a marked positive difference in the quality of my transplants (when ready to go in the beds, mid-late March) if I went that extra mile at this step?

I have do alot of those amendments that have been added in my raised beds' soil over the previous year, but this is my first year growing completely from seed, and I'm unsure if the younger seedlings need or would even benefit from that stuff in the 4-inch pot stage.