A steady narrow column
The conical crown remains restrained in width and gains height without spreading untidily.
Thuja occidentalis 'Smaragd' 17cm
Normal price
€13,50
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The legal guarantee concerns the plant’s conformity at delivery. It is not a guarantee of survival or growth for two years. Each issue is assessed taking into account the nature of the plant, its care and the conditions in which it is kept. Your statutory rights remain unaffected.
Thuja occidentalis ‘Smaragd’
Standing to attention. No sergeant required 🫡
- Narrow conical habit
- Emerald-green foliage
- Evergreen vertical line
- RHS AGM
Thuja occidentalis ‘Smaragd’ gives a space a clean vertical line that appears precisely drawn. Its narrow symmetrical crown is clothed in dense emerald-green sprays and retains colour remarkably well through winter. At an entrance, in a repeated row or as a calm evergreen background, it creates instant architectural elegance and gives the planting a timeless, polished appearance.
Young tips emerge a brighter green and gradually thicken the column, while small brown cones remain discreet. Its naturally conical habit is formal enough for structured design, yet the fine texture keeps it lively rather than rigid.
Thuja occidentalis ‘Smaragd’ holds a current RHS Award of Garden Merit, awarded in 1993.
What makes it special
Narrow proportions, dense upright sprays and winter green make Thuja occidentalis ‘Smaragd’ a benchmark for clean evergreen lines.
Green that persists
Glossy emerald foliage retains its winter colour better than many other arborvitae selections.
Dense upright sprays
Flattened branchlets stand vertically and fill the outline in many layers.
Why you will love it: it creates the long, calm green line an entrance or screen needs, without a bulky crown.
In the garden & on the balcony Placement & plant combinations Vertical green rhythm · sun to light shade · mature spread 1–2m.
A vertical green rhythm
Use at an entrance, in a narrow evergreen screen or as repeated columns, in sun to light shade. Space roughly 80–100cm centre to centre for a screen, or around 2 m or more for separate crowns, according to their eventual spread.
Columns and low movement
The formal vertical line balances beautifully with low tufts, soft curves and seasonal flowers at its feet.
- Hakonechloa macra — soft green curves on the cool, partly shaded side, in soil that retains moisture.
- Heuchera ‘Obsidian’ — broad dark foliage for clear textural contrast.
- Geranium ‘Rozanne’ — low blue flowers in a bright, cool and well-drained foreground.
Care at a glance
Light
Sun to light shade; good light keeps the conical column dense from base to tip.
Watering
Water deeply during establishment and hot spells; even moisture helps prevent the base from becoming bare.
Climate & hardiness
Very cold hardy, RHS H7; hot drying wind and prolonged drought can dull the foliage.
Safety
Harmful if eaten and a potential skin allergen; wear gloves when trimming and keep it away from children or animals that may chew it.
Detailed care Complete care guide Eight practical points for a dense base, clear tip and lasting evergreen colour.
Position
Sun to light shade; good light keeps the conical column dense from base to tip.
Watering
Water deeply during establishment and hot spells; even moisture helps prevent the base from becoming bare.
Soil
Moist but well-drained, moderately fertile soil; avoid both standing water and abrupt drying.
Feeding
A light spring feed is enough; excessive feeding produces soft growth and loosens the narrow outline.
Seasonal behaviour
Very cold hardy, RHS H7; hot drying wind and prolonged drought can dull the foliage.
Pruning & clearing
Remove only dry tips and shoots that break the column; do not cut deeply into bare old wood. Avoid removing the central leader unless you are intentionally limiting the final height.
Safety
Harmful if eaten and a potential skin allergen; wear gloves when trimming and keep it away from children or animals that may chew it.
Reading the plant
Browning inside the crown is often normal renewal; dry tips or thinning at the base call for a check of watering, wind and competition.
Development over time How the column rises Three stages from a young central axis to the narrow mature conical crown.
One clear axis
The young central stem organises the first upright lateral sprays.
Column thickening
Each season adds new layers without a large increase in width.
Mature green spear
The symmetrical conical crown retains a clear tip and dense base.
Mature habit & dimensions
established mature plantHeight 4–6mSpread 1–2mNarrow symmetrical conical column
At maturity, Thuja occidentalis ‘Smaragd’ forms a narrow, symmetrical conical column with persistent emerald-green foliage. It supplies privacy and vertical rhythm where a broad evergreen crown would take too much room.
Form through time
two real statesReal change in habitEmerald green throughout the year
One clear axisThe young central stem organises the first upright lateral sprays.
Mature green spearThe symmetrical conical crown retains a clear tip and dense base.
The two studies show how the central leader and short lateral sprays build the narrow column.
What to expect after planting: The central axis continues upwards while lateral sprays fill the column from the base. Its final narrow line becomes clearer each year, provided the leading tip remains intact.
History & origin Cultivar origin D. T. Poulsen · Kvistgård, Denmark · around 1950
Thuja occidentalis ‘Smaragd’ is associated with the D. T. Poulsen nursery in Kvistgård, Denmark, around 1950. It is an improved selection related to the older ‘Kelleriis Viridis’, with a narrow conical habit, upright branches and glossy green foliage that retains its colour in winter.
As it spread beyond Denmark, it acquired different market names. Pépinières Minier introduced it to France in 1963 as ‘Emeraude’, while in North America it became widely known as Emerald Green. Its accepted cultivar name remains ‘Smaragd’.
In 1993, the Royal Horticultural Society granted it the Award of Garden Merit, which it still holds.
Greenleaf for Plant Nerds Science nobody asked for Botanical details for anyone curious about what lies behind the plant’s appearance
Tiny glands on the leaves
In the species Thuja occidentalis, the small scale-like leaves carry conspicuous resin glands. A green “fan” consists of many small shoots with leaves pressed against them, rather than one broad leaf.
Cones in miniature
The species’ mature cones are around 7–12 mm long and have five or six pairs of leathery scales. They are reproductive structures of the conifer, not fleshy fruit.
Frequently asked questions
Answers about its natural shape and changes you may notice.
01Why are a few inner leaves turning brown?
Older foliage can be renewed inside the crown. If outer tips or whole branches also dry out, first check moisture around the roots and drainage.
02Can it stay permanently in its 17 cm pot?
The small pot is its current purchase size. As it grows, it needs a larger pot with drainage or a position in the ground.
03Should the tip be cut to make it denser?
No. Its natural conical shape develops around the central leader. Removing it makes sense only when deliberately limiting height.
04How tall can it become?
Over time in suitable conditions it can reach around 4–6 m, with a spread of approximately 1–2 m. It is not permanently dwarf; pot cultivation and pruning change its development.
05Does it remain green in winter?
Usually yes: clear winter green is characteristic of this cultivar. Drying wind or root problems can nevertheless affect the foliage.
06Will a bare old branch turn green again?
Do not rely on it. Avoid trimming deeply behind the green zone and confine corrections to shoots that retain foliage.
📦 Your plant travels protected
Every order is prepared with care so your plant arrives upright, secure and safe.
Individual protection
Plants in pots with a capacity of 3 litres or more are placed in individual boxes that hold the pot securely and reduce the risk of tipping over.
Sturdy packaging
We use reinforced cardboard designed to protect against impacts and vibration during transport.