Did you check the PH. Sometimes outdoor topsoil can become too acid or too alkaline from rainwater. rainwater is getting worse especial;y is urban areas.

Herbus
Herbus Reviewed by Herbus on . Necrotic spots, stunted growth. 15 day old seedlings still working on the first set of 3 leaves. Since the first bladed leafs came out there have been necrotic (dark blue almost purple) spots on the leaves beggining with the outside. The growth has obviously been stunted to an almost complete stop. I have proper lighting, temp, and watering techniques. The thing I believe it might be is the soil I use. It is the same soil I used on a last grow, but it has been outside for a while and I believe maybe it dried out too much. Rating: 5