danica eastern globe cedar


We bought some danica eastern globe cedars 3CG to plant in the containers on our deck.
Could you please advise the right maintenance schedule for this type of cedars when planted in the planters?
Soil,watering, fertilization and maybe some other tips ;)
Cedars are labeled with Hardiness Zone 3b , do you think we could keep the planters outside during the winter?
We live in Toronto and planters are insulated with1/2″ styrofoam from inside.


Thuja occidentalis “Danica” should do well in an outdoor container, and can provide interest in all four seasons.   You may find that growth is slower, and that the cedars don’t reach the full size indicated on the tag – this is typical of evergreens and other shrubs and trees grown in containers.  A good commercial container planting medium will be fine for your cedars as they are not overly particular about their soil. Good drainage is essential.  Any plant in a container will require more frequent watering, and cedars in particular prefer average-to-moist conditions and should not be allowed to dry out completely.  Fertilizing should not be necessary, but your cedars will benefit from a mulch of organic material such as compost, layered on top of the container soil.

Your containers’ insulation will be helpful for overwintering your cedars.  In Toronto, our rule of thumb is that plants that can be overwintered in containers should be hardy to a couple of zones below ours, i.e., to a zone 4.  Cedars hardy to zone 3 stand a very good chance of overwintering successfully.  Make sure that you continue to water your cedars through the fall before the weather freezes.  They can be susceptible to wind damage, so their containers should be moved into a sheltered location and a layer of mulch should be added to the top of the container soil.  If your cedars are located in a sheltered spot, it should not be necessary to wrap them with burlap over the winter.