How To Plant Emerald Cedar Trees

A cultivar of American arborvitae or Eastern white cedar, the emerald cedar (​Thuja occidentalis​ 'Smaragd') grows to 15 feet tall and 4 to 5 feet wide. Often planted close together to form tall hedges, it has a narrow, conical shape when planted alone.

Reputed to keep its emerald hue better than most other evergreens in U.S. Department of Agriculture plant hardiness zones 2 to 7, it does so most dependably in humid climates. Because "smaragd" is the Danish word for emerald, the tree is often sold under the trade names Emerald or Emerald Green.

1. Dig a Trench or Hole

Dig a trench for multiple plants on a site with full sun and rich, loamy, well-draining soil if you want to make a hedge of closely planted emerald cedar trees. Make that trench as deep as the cedars' root balls and whatever length you wish the hedge to be. If you're only planting a single cedar, dig a hole as deep as the tree's root ball and three times its width.

2. Space Emerald Cedar Trees

Place cedars for hedging in the trench, still in their pots, so their trunks are 2 feet apart. Use a measuring tape so the trees will be evenly spaced. If you need to determine how far from a neighboring tree a single, freestanding cedar should be planted, add the mature width of both trees together and divide it by half.

3. Loosen Root Balls

Knock the cedars' pots lightly against the ground to loosen the root balls so that they slide out easily. If they don't emerge easily, cut away their plastic pots with a sharp knife. Leave most of the burlap on balled-and-burlapped trees, as that material decays quickly in the soil, but remove any burlap around the top of the root ball.

4. Uncoil the Roots

Uncoil and tease apart any roots that appear to have been circling the pot. Cut back, with sharp pruning shears, any that now extend below the original root ball.

5. Position the Trees

Set the root balls of the cedars into the trench, and continue until all of them are in place. Remove any ropes or wires that might be securing the burlap.

6. Cover With Soil

Shovel soil back into the trench or hole until it is half filled. Stop shoveling and pack the soil down firmly around the roots, either stepping on it or tamping it with gloved hands. Water those roots thoroughly with a hose. Continue adding more soil until the trench or hole is full and water the cedars again.

7. Top With Mulch

Spread 2 to 4 inches of an organic material, such as wood chips, over the soil, but keep that landscape mulch at least a couple of inches away from the trunks. Water immediately after planting, making sure to saturate the roots. Keep the planting site moist but not soggy for the first four weeks after planting and while the roots establish themselves into the planting site. Thereafter, make sure the cedars get at least 1 inch of water per week.