Abies firma seedlings large enough for grafting understock are very hard to find! I purchased 3"-6" Jiffy Plug Abies firma seedlings to grow for a year and use for grafting next year. I've never dealt with Jiffy Plugs. Do I need to remove the outer covering material before potting up? By looking at the small roots protruding, removing the outer material may be very time consuming. I have 100 of these to pot. I recall hearing someone say that root rot can be a problem if the Jiffy Plug isn't torn apart/removed. What size pot do you recommend? I thought about using a 4.5" pot and the grower suggested 1 gallon pots. Any help is greatly appreciated!