Students for Stewardship The Cork Board
← Back to the library

'DeGroot's Emerald Spire'

Thuja occidentalis (THU-ya ock-sih-den-TAH-liss)

Family: Cupressaceae Unknown Understory (15-40 ft)

'Degroot's Spire' is a dwarf cultivar of the evergreen, conifer named American arborvitae or eastern arborvitae. It is a compact and slow-growing small tree or large shrub with a narrow conical habit. The leaves are flat, twisted sprays of scale-like rich green foliage and have a citrus or fruity fragrance. It is the perfect evergreen for small vertical spaces in the garden. Pruning of its side shoots when the plant is young may be necessary to maintain its narrow habit. It is a member of the Cupressaceae or cypress family. The genus name, Thuja , is Greek and is the name of a type of juniper. The species name, occidentalis, means of the "western world." The cultivar is named for Constant DeGroot, who was propagation and production manager for a nursery in Toronto, Ontario, Canada. The plant was first introduced in 1980. 'Degroot's Spire' grows best in full sun to partial shade and loamy, moist, well-drained soils. It prefers acidic to neutral soils. Mulching is required to maintain moisture at the plant's roots. The plant is intolerant to dry conditions and should be planted in sheltered sites to prevent exposure to winter elements and wind damage. This plant is susceptible to damage from snow and ice. The foliage may turn yellowish-brown or greenish-brown from cold exposure. It is tolerant of clay soil, air pollution, and black walnut. Pruning should be completed in the early spring before the new growth appears. Consider Degroot's Spire' as a specimen, accent, container, or patio planting. It serves well as a foundation planting or shrub border. This evergreen would add winter interest to a cottage or rock garden. Wear gloves and protective clothing when handling this plant. The foliage may cause some skin irritation. Seasons of Interest: Foliage: Spring, Summer, Fall, and Winter Quick ID Hints: majestic, dwarf, slow-growing, upright, pyramidal habit twisted, feathery-sprays, scale-like, medium green foliage foliage fragrance of citrus when leaves are crushed or bruised Pests, Diseases, and Other Plant Problems: 'DeGroot's Spire' has no serious insect or disease problems. Spider mites, leaf miners, bagworms, mealybug, and scale may be seen. Leaf blight will cause spotting of the foliage and leaf drop. It may also be affected by canker. VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 37 attributes.

How it fits the guild

Guild layer 2 - Understory (15-40 ft) Optimal soil pH Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Chamaecyparis obtusa 'Nana Lutea' Chamaecyparis thyoides 'Red Star' Picea laxa 'Conica'

Full plant profile

Growing Conditions
Plant type
Shrub; Tree
Life cycle
Woody
USDA zones
2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Available space
3 feet-6 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 15 ft. 0 in. - 30 ft. 0 in. | Width: 4 ft. 0 in. - 5 ft. 0 in.
Growth rate
Slow
Maintenance
Low
Canopy layer
2 - Understory (15-40 ft)
Form & Appearance
Habit / form
Columnar; Erect; Pyramidal
Foliage
Needled Evergreen
Leaf color
Green
Leaf value
Fragrant
Hairs present
No
Leaf detail
The leaves are fragrant, twisted, feathery sprays of scale-like medium green foliage. The leaves may be purplish-tinged during the winter months. A fruity fragrance is noted when the leaves are bruised or crushed.
Flower detail
Non-flowering
Wildlife & Ecology
Native status
Unknown
Play value
Easy to Grow; Fragrance; Screening
Food & Medicine

Uses (ethnobotany)

The species foliage was used by Native Americans as a medicine to treat scurvy.

Landscape Use
Landscape location
Coastal; Container; Patio; Small Space; Vertical Spaces
Landscape theme
Asian Garden; Cottage Garden; Rock Garden; Winter Garden
Design feature
Accent; Border; Foundation Planting; Hedge; Small Tree; Specimen
Garden tags
#needled evergreen #small tree #evergreen tree #pruning tolerant #container plant #full sun #dwarf #narrow form #slow growing #contact dermatitis #pyramidal #conifer #easy to grow #humidity tolerant #erect #small spaces #wet soils tolerant #foundation planting #rock garden #low maintenance #green leaves #winter interest #evergreen shrub #showy #fragrant leaves #evergreen #landscape plant sleuths course #hedge #shrub border #screen
Problems & Resistance
Insect problems
Pests of Conifers
Problems
Contact Dermatitis
Resistant to
Black Walnut; Urban Conditions

Planted at Hunnicutt

Nobody’s planted this one yet.