American Arborvitae varieties can be grown north well into Canada (zone 2). They survive where winter temperatures are as low as -35°F to -50°F. They are common as far south as southern Pennsylvania and into Virginia and California on the Pacific coast. Oriental arborvitae is more common in the hot southern regions of the US north to Virginia and in protected locations along the mild coastal areas up to Rhode Island.
Arborvitaes generally prefer full sun. While partial shade is desirable in regions where very intense summer sun might scorch them, arborvitaes tend to become ragged if grown in prolonged shade. Varieties having yellow foliage require day-long sun to maintain their stunning color. Though they tolerate either acid or alkaline soil, they prefer deep, moist, well-drained soil rich in organic matter and on the acidic side (pH 5.5 to 6.5).
These trees root easily and grow quickly. Plant 2 to 3 foot tall nursery stock in the spring or fall. Plant arborvitae whose roots are in a ball of soil and wrapped with burlap in spring to early summer. Plant container-grown plants anytime from spring through early fall.
For details on planting trees click here.
Staking
Their dense foliage and relatively small rootballs make newly planted arborvitaes vulnerable to wind in exposed sites. To prevent their being blown over or uprooted before they become established, drive 3 sturdy supporting stakes into the soil equidistant about two feet beyond the arborvitae’s foliage. Loop soft clothesline rope or cables wrapped with rubberized protection where they contact the tender tree bark around the plant stem and then secure the ties to the stakes. Do not put strong tension on them, as the young arborvitae stem needs leeway to move somewhat so it will grow strong. Check often to make sure the cables are not binding or injuring the trunk in any way. Remove staking once the roots are securely anchored in about 6 months.