The recommended time to plant evergreen trees, including cedar, is during spring, summer or early fall, notes the University of Wisconsin Extension. Avoid planting during late fall, as this does not give the tree enough time to get established before the cold weather. The foliage of trees planted later in the season tend to lose moisture faster than the roots can replenish it, causing injury or burn to the trees. Summertime planting should be avoided if possible as there is a greater likelihood of tree death from thermal shock and poor water distribution due to weak roots.
Select cedar trees with healthy foliage that does not have any shades of gray, yellow or brown. Unlike deciduous trees that grow new foliage, the needles of evergreens do not regain their color once they have discolored. Discoloration may be due to disease or drought. Look for sturdy branch structure and inspect trunk for signs of oozing sap. Select trees that have not been sheared into shape, as it can take a long time for the tree to regain its natural form.
The proper site is just as important for growth as the right planting time. Plant cedars in a full sun location for best growth. White cedar is somewhat tolerant of slight shade. Avoid planting in very windy or exposed sites, as this is likely to cause winter burn. The University of Wisconsin Extension recommends planting on the east or north side of the house. The majority of evergreen species prefer well-drained soil, and white cedar is also adapted to growing in moist, low-lying areas.
Irrigate the newly planted cedar on a regular basis for up to a year, watering deeply every week during very dry weather conditions. Adjust the water amount according to soil types, watering a little more frequently in sandy soil and a little less in heavier, slower-draining soils. Water young and established trees thoroughly in November, as this helps to minimize winter burn.