Topdecker, I used growbags for the first time last winter, stored roots in the garage until all frost danger was over in my area then moved them outside in the shade in June. I do have 2 windows in the garage so they got some light. They all budded out just as they would outside, actually had a few bloom in the garage. Have even more in there this year already! If you're planting herbaceous 12 gallon bags are probably overkill, don't think I have a herbaceous in anything larger than a 7 gallon, most fit in 3 gallon bags. 12 gallon would probably fit one of the huge Adelmans or Solaris woody roots easily
