While this is a good fertilizer, it is not a good planting medium. It packs, clumps and drys out easily. It just does not permit healthy root growth. I always use Pro-Mix or a brand with the same ingredients. This is a blend of equal parts of sphagnum peat moss, perlite and vermiculite.
Some manufacturers also add a weak fertilizer to the blend.
Pro-Mix is light weight, does not pack or clump, holds water very well, and promotes healthy root systems in seedlings. Most importantly, it is sterile and the sphagnum peat helps prevent damping-off fungus. Damping-off fungus is the culprit when seedlings look healthy for a day or so, and then fall over and die. Next, we'll need to get our containers ready. Ideally, you should probably use peat pots or Jiffy-7 pellets.