I am planting a row of emerald cedars along my backyard fence to create a privacy screen. In mid-April I planted 6 cedars that are 5-6 feet high. I plan to plant around another 10 cedars to complete the row.
Although it is only late May, temperatures are at mid-summer levels. Is it too late in the spring now to plant more cedars? At this point should I wait until the late summer to plant more?
Emerald cedars (Thuja occidentalis ‘Smaragd’ or Arborvitae) are very attractive trees with thick green foliage and a narrow, pointed growth habit. They require full sun and consistent watering to maintain good growth throughout the year. However, they are most successful being used as specimen plants in a sunny spot rather than as a hedge for privacy; they retain their pyramidal shape as they grow but can be pruned judiciously in order to maintain them as a hedge. Cut back only the new growth when pruning. [Actually, many consider the native white cedar (Thuja occidentalis) to be the best cedar for creating a hedge in Ontario–maintaining sufficient moisture and humidity for growing the Emerald cedar can be a challenge]. It is important that once planted, the soil is kept moist–do not let the soil dry out; but make sure that the soil has adequate drainage–excessive water around the roots can cause dieback. Browning of the foliage due to inconsistent watering is one of the main problems with growing this cedar. And, as is the case with most conifers, they may suffer some browning during the freeze-thaw cycles during the late winter months–the ground remains frozen as the air becomes warm; the plant is unable to take moisture in through its roots to replenish moisture loss due to warmer temperatures.
Even though autumn might be a better time to plant more cedars, it would not be too late to plant them in late May as long as the temperatures are a bit cooler than mid-summer levels and there is sufficient moisture in the ground.
Good luck with your hedge.