How often did you water it? What kind of planting soil did you use previously?

I watered once a week more or less (less in winter I think) and used miracle grow potting soil with sand and perlite mixed in.
Sue

I don't know your growing conditions, but seeing your zone, you must have yours indoors. Once a week might be too much for them although it sounds like your drainage should be okay. Do you have saucers under the pots? If water collects in the saucers, you may need to pour it off so the plants are not sitting in it.