Thuja occidentalis 'Smaragd' / Emerald Green arborvitae

Thuja occidentalis 'Smaragd' is a narrow upright selection of arborvitae with fine branchlets and glossy, emerald-green foliage that does not become bronze in winter. It is an extremely popular plant for use in hedgerows and borders. After 10 years in the landscape, a specimen will be considered mature at roughly 6 feet (2 m) tall and 18 inches (50 cm) wide, rate of growth approaching 1 foot (30 cm) per year.

This cultivar originated as a seedling selected in 1950 by D. T. Poulsen Nursery, Kvistgaard Denmark. It is marketed in the U.S. under the trade name Emerald Green™, a designation that is generally rejected by nomenclature purists.

Thuja occidentalis 'Smaragd' — an example of its most-common use.
Photo by Sam Pratt, courtesy of Conifer Kingdom inc.



These are everywhere near me, but it's easy to see why because they're very striking. Most people allow theirs to grow multiple leaders, but I keep mine to a single leader.


beautiful trees. I've had mine for a year and they have dead branches in the interior. What can I do about this?

Maxwell Cohn

you should cut them away or ignore them. This is typical behavior for these kinds of plants.


Does anyone know the “spread growth rate?” I see the height growth rate in every article but not the spread rate. I have just planted several of these, spaced 2.5’ apart and am anxious for them to fill in. Comments anyone? Thanks!!

Maxwell Cohn

for arborvitae, spread is usually about 25% of the height.


Does root growth cause wall or sidewalk damage when planted at least 3 feet away?


what is the mature height and width on these?

Maxwell Cohn

Hi Robin ... these are considered to be mature at 6 to 8 feet tall and 1-quarter as wide. Ultimate height is 30 to 40 feet tall and still 1-quarter as wide.


We had snow and ice. My trees are 3-4 yrs old and have broken branches. Can they be saved?

Maxwell Cohn

if the branches are truly broken, they cannot be saved. You should prune them away when convenient. Arborvitae are notoriously bad in parts of the country that are prone to snow and ice.


My Arbodivte has a lot of brown on it what should I do? Am I watering it to much?