You can't go wrong with the industry standard - MiracleGro Potting Mix. MiracleGro sells a number of different soils but the PM is the way to go.
MG PM has nutes for 3 months so those afraid of adding nutes to water can relax. Couple of observations re: MG PM.
If you are going to be putting seedlings into dirt tomorrow, be sure your soil is inside at least 24 hours before you need it. It's a pain to get
everything set up and discover that the bags of dirt out in the shed are too wet or too frozen. The bags should be inside 24 hours at least.
The only time I've cursed MG PM is when first putting seedlings into dirt. The PM has ground up wood chunks in it as part of its organic nutes.
Twice I have had seedlings perish because when I explored I discovered that the seedlings fight for the surface was hindered by a chunk of wood.
So now I kinda hand-sift through the soil pulling out any chunk more than an inch long.
Watering seedlings that are toothpick size and 7 inches long is a chore as it is too easy to harm the toothpick when watering. So I use a syringe
with the needle removed to dribble a few cc of water on the tall, skinny ones.
Good luck, BigSteve.
