How to Care for Emerald Green Arborvitae | Keep Them Dense & Green

For the full breakdown, see our best Smaragd Emerald Green Arborvitae guide.

Emerald Green arborvitae is a popular evergreen for good reason — it forms a dense, upright privacy screen that stays dark green through winter. Getting the care right is mostly about matching the plant’s needs: sun, soil, and water. Too much shade, soggy ground, or a heavy hand with the pruners are the fastest ways to turn a healthy hedge into a brown, sparse one.

The sections below cover planting, watering, pruning, and the winter protection that keeps these trees looking sharp for decades.

Planting Emerald Green Arborvitae: Sun and Soil Needs

Emerald Green arborvitae performs best in full sun, which means at least 6 hours of direct light daily. It tolerates partial shade, but dense foliage depends on that sunlight — the more shade the trees get, the thinner the growth becomes.

The soil matters just as much. Oregon State University’s extension guidance points to moist, cool, deep, well-drained loamy soil as the ideal. Poorly drained or soggy sites are a genuine problem; standing water around the roots invites root rot, the most common killer of this cultivar.

When you’re ready to buy, spacing drives the whole look, so get it right at planting time.

For a privacy hedge, space plants roughly 3–4 feet apart. That gap allows air circulation, which reduces disease pressure, and lets each tree keep its natural shape without crowding. Closer spacing forces the trees to compete and thin out at the base.

Watering and Mulching for Newly Planted Trees

Watering is the single most important job during establishment. Newly planted Emerald Green arborvitae need consistent moisture for the first few years — this is not a drought-tolerant plant until it is well rooted.

The reliable schedule looks like this:

• First few months: Water twice weekly, deeply enough to soak the root ball.
• Next year or so: Drop to a weekly deep watering.
• Established trees: About 1/2 inch of water weekly, more during hot, dry stretches.

The North Central Conservation District’s plant guide stresses keeping the soil moist but not saturated. Check the soil a few inches down; if it’s dry, water. If it’s still wet, wait.

Mulch helps hold that soil moisture and keeps roots cool. Apply 1–3 inches of organic mulch over the root zone, and keep it pulled back from the trunk — mulch piled against the bark traps moisture and invites rot. Replenish the layer as it breaks down.

Pruning Emerald Green Arborvitae: When and How

Light pruning in early spring, just before new growth begins, is all an Emerald Green arborvitae needs. The goal is to tidy the shape, not to shrink the plant.

The one hard rule is this: do not cut back into bare, old wood. Emerald Green arborvitae does not grow new foliage from old wood, so a cut down into the brown interior leaves a permanent bare spot. That mistake is the most common reason a hedge develops ugly holes.

What pruning is acceptable:

• Trim back the previous season’s new growth by a few inches.
• Shear lightly to maintain a flat or tapered hedge line.
• Remove dead, broken, or diseased branches at any time of year.

Heavy shearing, topping, and hard cuts into old wood all weaken the plant and destroy its natural form. If your trees are already too tall for the spot, replace them rather than topping them — a topped arborvitae never recovers its shape.

Fertilizer is rarely part of the routine. Most soil supports these trees without help, and overfeeding pushes weak, soft growth. Only if growth looks sparse or slow, it’s worth applying a balanced fertilizer sparingly in early spring. Rely on your own knowledge of soil health here, since regional conditions vary.

Winter Protection and Common Problems

Cold itself is rarely the issue; winter damage comes from wind, snow, and deer.

Exposed, windy sites dry out the foliage, turning it brown in late winter. For a wind-swept location, consider a burlap screen on the prevailing-wind side. In snow-heavy areas, the guide from Oregon State University recommends brushing heavy snow off the branches promptly and tying or wrapping the trees loosely with burlap to prevent branches from splitting under the load.

Deer browsing is another real threat. Burlap wrap offers physical protection where deer pressure is high, and it doubles as snow protection.

The most common problems with Emerald Green arborvitae trace back to care mistakes, not pests:

• Overwatering or planting in wet soil — root rot, yellowing, dieback.
• Deep shade — thinning foliage, weak growth.
• Heavy shearing or topping — bare wood that never fills back in.
• Exposed windy sites — winter desiccation and brown tips.

When snow or deer are likely problems, act before winter arrives. Wrap loosely, brush off snow after storms, and prune any broken limbs in spring. Healthy, well-sited trees shrug off most of what winters throw at them.

When you’re ready to add these trees to your yard, our roundup of the best Emerald Green arborvitae options can help you choose the right plants for your space.