Emerald Green Arborvitae

Emerald Green Arborvitae (Thuja occidentalis 'Smaragd') is the answer when you need height on a boundary and have almost no width to give it. It grows to about 4m tall but only 1.2m across, holding a dense bright green column without a frame and without hard pruning. Planted 60cm apart it forms a formal screen that reads more like a wall than a row of shrubs.

Why you'll love it

• Height without the footprint. Four metres of screening from a plant only 1.2m wide, so it fits beside a driveway or in a bed a metre deep.
• It holds its own shape. The naturally conical, tightly furnished habit gives a tidy screen without shearing.
• Cold and wind are not a problem. Frost hardy and wind tolerant, which is why it performs in southern gardens where many evergreen screens struggle.
• Drought tolerant once settled. After two summers it asks far less water than a comparable broadleaf hedge.
• Keep it away from pets. The foliage contains thujone and is toxic to cats and dogs if eaten.

Where it works best

Narrow screening and privacy. Plant 60cm apart in a single row. The tight spacing is deliberate: these plants are narrow, so they need to be close to close the gaps. Expect a solid face within three to four seasons.

Formal hedging and shaping. Fine even foliage holds a sharper clipped line than most broadleaf alternatives, and it takes topiary work well.

Pots and entries. A 500mm or larger pot carries a plant to around 2m, and a matched pair either side of a doorway is the classic use. Keep the water up, because containers dry fast.

Growing Emerald Green Arborvitae in Australia

Position and climate. Full sun, all day if you can manage it. This is a plant for cool temperate, warm temperate and Mediterranean gardens: Victoria, the southern tablelands, Adelaide, Perth and cooler districts of New South Wales. It dislikes humid subtropical summers and browns off from the inside in warm northern coastal gardens.

Soil. Drainage matters more than fertility. On heavy clay, plant on a raised mound with compost and coarse grit worked through, because wet feet over summer is the usual cause of failure.

Water and feed. Deep soak twice a week through the first two summers, then taper to occasional watering in dry spells. Never let a young plant dry out completely, because brown patches on a conifer do not reshoot. A slow release fertiliser in early spring is enough.

Pruning. Light trimming in spring and again in early autumn if you want a formal face. Always stay within the green growth, because cutting into bare old wood leaves a permanent hole.

What to expect when it arrives

It is grown in 140mm packs of ten, 200mm packs of six, 250mm packs of three, single 300mm plants and advanced 400mm stock, from about $148.95 to $343.95. Multipacks are the value option for a long boundary and catch up within a few years. The 300mm and 400mm sizes arrive with real height and suit a short run or a pair of pots.

Plants travel upright and are delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery. Growth is steady rather than quick, which is why the finished hedge stays manageable. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Compare hedging and screening plants
• Browse the full range of trees by mature size
• How to prepare a garden bed before planting

Common questions

How far apart should I plant it for a hedge?

Sixty centimetres apart in a single row. These plants are narrow, so the usual one metre hedge spacing leaves gaps that take years to close over.

How fast does it grow?

About 20cm to 30cm a year, so allow five to seven years to take a 200mm plant to a 2m screen. Larger stock shortens that considerably.

Will it grow in a humid subtropical garden?

Not well. It is built for cool and temperate climates and resents humid summers, which shows up as browning inside the plant. In warm humid coastal gardens a lilly pilly is the better investment.