Not planting any myself but in the past had a family member plant over 30 acres of red pines plugs in the fall and I had the same help plant regular bare root white spruce in a different spot but actually better soil the following spring. Had a terrible dry summer that year and I lost probably over 80% of the spring planted but the stuff planted the fall prior fared much better. Maybe the fact of plugs vs. bare roots had something to do with it but I would not hesitate to do plugs in the fall