Potted outdoor trees/plants
Will Aborvitae withstand Mn winter in pots? What size pot is necessary? What other tree/plant/shrubs would survive? We are in a 4-story building in St. Louis Park and wish to have greenery on the rooftop. Thank you for your help. Margaret Roe 612-382-5985 cell
Hennepin County Minnesota
The short answer is that they will not survive. The temperature of the soil in a pot approaches the outdoor temperature. The temperature of the soil in the ground, several inches down, rarely goes below 20 degrees. That's why plants survive in the ground but not in pots.
If you want "greenery" in your rooftop, there are plenty of annuals that will give you color and foliage all summer long. You can even through in some perennials (but don't expect them to survive the winter). I would not suggest larger plants such as trees (arborvitae) or shrubs.
If you are considering a "green roof" instead of planting in pots, read here: