Denomination: 'Bulthouse'
Trade name: Sprinter
Botanical Name: Buxus sinica var. insularis
Applicant/Holder: Spring Meadow Nursery, Inc.
12601 120th Avenue
Grand Haven, Michigan
United States of America
Breeder: John Bulthouse, Norton Shores, United States of America
Agent in Canada: BioFlora Inc.
38723 Fingal Line
R.R. #1
St. Thomas, Ontario
N5P 3S5
Tel: 519-631-6241
Application Date: 2012-09-12
Application Number: 12-7750
Grant of Rights Date: 2016-06-30
Certificate Number: 5282
Grant of Rights Termination Date: 2036-06-30

Variety Description

Variety used for comparison: 'Green Gem'

Summary: The plants of 'Bulthouse' are taller with broader leaves than the plants of 'Green Gem'. The shape of the apex of the leaf blade of 'Bulthouse' is obtuse and weakly retuse whereas the apex of the leaf blade of 'Green Gem' is acute and the tip may be blunt.


SHRUB: evergreen type, bushy-rounded growth habit, compact shape, many branches, dense foliage
STEM: medium thickness, weak to medium intensity of anthocyanin colouration, edged shape, light green with red-brown tones, no twisting

PETIOLE: present
LEAF: opposite arrangement along stem with pairs of leaves in a spiral pattern, simple type, absent or very weak fragrance
YOUNG LEAF BLADE: dark green (RHS 143B-C) on upper side
LEAF BLADE: elliptic and obovate shape, obtuse and weakly retuse shape of apex, cuneate shape of base, entire margin, no variegation
LEAF BLADE (UPPER SIDE): medium to strong glossiness, absent or very sparse pubescence, brown green (RHS 147A)
LEAF BLADE (LOWER SIDE): absent or very sparse pubescence, dark to light green (RHS 144A-B) with dark green (RHS 144A) at margin

Origin & Breeding History: 'Bulthouse' was discovered and developed by the breeder, John Bulthouse, in Norton Shores, Michigan, USA. It was discovered in July 2005 as a mutation of the Buxus sinica var. insularis variety 'Winter Gem' in Norton Shores. 'Bulthouse' was selected during that same year for its plant growth habit, plant vigour and hardiness. It was first asexually propagated by hardwood cuttings in November 2005 in Norton Shores, Michigan, USA.

Tests & Trials: The comparative trial of 'Bulthouse' was conducted as an outdoor irrigated container trial during the summer of 2014 at BioFlora Inc. in St. Thomas, Ontario. The trial included a total of 12 shrubs of the candidate variety and 10 shrubs of the reference variety. All shrubs were grown from 5.5 cm liners that were each planted into a 9 litre container in June 2013. The trial was arranged in rows with approximately 60 cm spacing between plants. Observations and measurements were taken from 10 plants or parts of plants of the candidate and reference variety on August 25, 2014. The flowering characteristics were not assessed. All colour determinations were made using the 2007 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'Bulthouse' with reference variety 'Green Gem'

Plant height (taken during late summer) (cm)

  'Bulthouse' 'Green Gem'
mean 30.2 20.5
std. deviation 3.86 4.50

Leaf blade width (cm)

  'Bulthouse' 'Green Gem'
mean 1.3 1.0
std. deviation 0.09 0.10

Click on image for larger view
Boxwood: 'Bulthouse' (left) with reference variety 'Green Gem' (right)

Click on image for larger view
Boxwood: 'Bulthouse' (left) with reference variety 'Green Gem' (right)

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Boxwood: 'Bulthouse' (left) with reference variety 'Green Gem' (right)

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