Arborvitae (Thuja occidentalis)
Also known as white cedars, arborvitaes are evergreen trees with scale-like needles. Trees are dense, making them ideal for natural screens and hedges. There are many varieties of arborvitaes that range in needle color and mature size.
Hardiness- zones 2 through 8
Growth Rate- slow
Mature Shape- stiff, narrow-pyramidal
Height- 30 to 40 feet
Width- 10 to 15 feet
Site Requirements- Arborvitaes grow best when planted in full sun with moist, well-drained soils, but can adapt to adverse soil conditions.
Features- Needles of arborvitae are green in summer and may turn yellow in winter.
Recommended Varieties for Iowa- ‘Brandon’ arborvitae has a narrow, pyramidal shape and reaches 12 to 15 feet tall. ‘Danica’ is a small, globe shaped arborvitae that has emerald green needles and reaches 1 to 2 feet tall. The variety ‘Little Gem’ has dark green needles, a broad globe shape and reaches 2 to 3 feet tall. See the link below for a publication on arborvitaes that are well suited for Iowa landscapes.