I think your recipe would be too water retentive in a pot. I like using bumper crop as about 10-15 percent of a container mix, but it does hold a lot of water, just like peat. I used 5 parts aged pine bark, one part bumper crop and one part perlite to transplant my seedlings into. That's close to the 5-1-1 mix that's very popular in the container forum. It provides enough nutrition and water retention for two or three weeks before planting out, so you don't need to fertilize. A little biotone wouldn't hurt, but I wouldn't add any other dry fertilizer.

That's what I thought. 5-1-1 it is! Thanks for your help Ohio.