What Can Mix With Emerald Green Arborvitae?

Shrubs

• Choose slow-growing, low shrubs that won't compete with the emerald green arborvitae's root system. The dwarf fothergilla -- Fothergilla gardenia -- grows to 3 to 5 feet tall with a 4-foot spread. This deciduous shrub has thick, blue-green foliage and blooms with aromatic white flowers in spring. It is hardy in USDA zones 5 to 8 and prefers sun to partial shade and well-drained soil. Dwarf fothergillas tolerate drought. The Blue Star juniper -- Juniperus squamata "Blue Star" -- has blue-green needles and grows into a dense, compact mound. It reaches heights to 3 feet with a 4-foot spread and is hardy in zones 4 to 8. Blue star junipers prefer full sun and well-drained soil.

Ground Covers

• The blue lagoon juniper -- Juniperus conferta "Blue Lagoon" -- has blue-green, awl-shaped needles and grows slowly to 6 inches tall with a wider spread. This evergreen spreads into a dense mat of foliage that can attain a plum hue in winter. It prefers sun to light shade and tolerates drought and salt. Blue lagoon junipers are hardy in USDA zones 6 to 8. The cranberry cotoneaster -- Cotoneaster apiculatus -- is hardy in zones 4 to 7 and grows to 3 feet tall with a 6-foot spread. This evergreen has dark foliage and produces an abundance of red fruits in autumn. Craberry cotoneasters prefer sun to partial shade and tolerate drought and a range of soils.

Grasses

• Ornamental grasses have fibrous, spreading root systems that help prevent erosion and runoff near your Emerald Green arborvitae. Complementary species include tumble grass -- Eragrostrum spectablis. Hardy in USDA zones 5 to 8, this grass grows to 2 feet tall and produces red to purple inflorescences in last summer. It has gray-green foliage and grows well in full sun and sandy to poor soil. Blue lyme grass -- Elymus arenarius -- has blue-green, flat fronds and grows in clumps from 3 to 4 feet tall. It produces blue-green flower spikes in summer. Blue lyme grass is hardy in zones 4 to 10 and grows well in sun and dry soil.

Perennials

• Choose sun-loving, red-blooming perennials to add a splash of complementary color near your emerald green arborvitae. Red valerian -- Centranthus ruber -- blooms in spring with spikes of bright red, white and pink flowers. It thrives in sites with full sun and well-drained to dry soils and is hardy in USDA zones 5 to 8. Red valerian grows to 3 feet tall. Red-hot poker -- Kniphofia uvaria -- grows to 5 feet tall and blooms in summer with tall, red flowers. It prefers full sun and well-drained soil and is hardy in zones 5 to 9.