The Eastern arborvitae (Thuja occidentalis) and its cultivars have been commonly planted landscape-plants in the Midwest, especially suited as year-round screening-plants. As its foliage is a favorite food of foraging deer, its use in many landscapes is now limited.

Giant Western Arborvitae (Thuja plicata), native to the Pacific Northwest, has proven to be far less attractive to foraging deer and has proven to be winter hardy in our zone 4 climate. Plantings of T. plicata at the Arboretum in 1982 now measure 23 feet tall and 16 feet in spread. They have developed single leaders that hold up well during ice and snow storms that so often malformed the multileadered T. occidentalis.

Thuja plicata is also more shade tolerant than T. occidentalis, so that its lower branches are held into maturity. As a screening or hedge plant, it can be planted in shaded areas where T. occidentalis would fail.

Planted at the Arboretum in 1996, Thuja plicata 'Excelsa' now measures 24 feet tall and 11 feet wide. Its narrow, spire-like form allows it to be planted as a screening plant in more confined areas. This fast growing "instant privacy" conifer has glossy, deep green foliage.

Spring Grove^®, another promising selection was planted in 2000. This plant with very dark green foliage now measures 10 feet tall and 6 feet wide.

The Goldtip arborvitae ('Elegantissima'), probably a hybrid between T. occidentalis and T. plicata, bears gold-tipped course-textured foliage on a broadly pyramidal plant. In coming years, other cultivars of the deer resistant Giant Western Arborvitae will be evaluated in the arboretum. My top choice in 2007 is Thuja plicata 'Excelsa'!