Sounds good, but you'll want to check to make sure that there are no fertilizers in it.
I also find that organic potting mix is really dense.... I found this out the hard way when one of my scheffleras got really bad root rot. You might find that the soil doesn't drain well - if that's the case, mix it with some sand or fine gravel, especially near the bottom of the pot, so things can drain properly, and the roots of the plants don't get smothered.