Denomination: 'Bulk'
Trade name: Quick Fire
Botanical Name: Hydrangea paniculata
Applicant/Holder: Spring Meadow Nursery, Inc.
12601 120th Avenue
Grand Haven, Michigan
United States of America
Breeder: Rein Bulk, Boskoop, Netherlands
Agent in Canada: BioFlora Inc.
38723 Fingal Line
R.R. #1
St. Thomas, Ontario
N5P 3S5
Tel: 519-631-6241
Application Date: 2004-10-01
Application Number: 04-4426
Grant of Rights Date: 2008-11-21
Certificate Number: 3398
Grant of Rights Termination Date: 2026-11-21

Variety Description

Variety used for comparison: 'DVPPinky' (Pinky Winky)

Summary: 'Bulk' has a shorter leaf blade and wider inflorescence than 'DVPPinky'. The density of sterile flowers with a large calyx is sparse for 'Bulk' while it is medium to dense for 'DVPPinky'. 'Bulk' has fewer large calyxes per inflorescence than 'DVPPinky'. 'Bulk' has weaker anthocyanin colouration in the mature large calyx than 'DVPPinky'. 'Bulk' flowers earlier in the season than 'DVPPinky'.


PLANT: upright, hardy to zone 4, flowers very early

LEAVES: medium green on upper side, no variegation, no glossiness, elliptic to ovate, acute apex, acute base, no lobing, finely serrate margin

INFLORESCENCE: flowers with small calyx conspicuous, flowers with large calyx arranged in two or more circles, conical shape, sparse density of sterile flowers with a large calyx
LARGE CALYX: few in number per inflorescence, absent or very weak anthocyanin colouration, medium anthocyanin at maturity, white maturing to blue pink, four sepals, sepals moderately overlapping, margin incisions absent to very sparse, sepals round
SMALL CALYX: weak anthocyanin colouration, white, weak anthocyanin colouration of anthers

Origin & Breeding History: 'Bulk' was developed by the breeder, Rein Bulk, in Boskoop, The Netherlands. The variety originated from a chance cross made between two unknown parents of Hydrangea paniculata. In 1991 a single plant was selected by the breeder based on early flowering, flower colour and excellent growth characteristics. Asexual reproduction of the new variety was first conducted in the summer of 2002 by softwood cuttings.

Tests & Trials: The tests and trials for 'Bulk' were conducted in an outdoor trial at BioFlora in St. Thomas, Ontario in the summer of 2007. The trials included 15 plants of each variety. All plants were grown from 12 cm liners, planted into 2 gallon containers in May 2004 and transplanted into 3 gallon containers on July 2, 2004. Observations and measurements were taken from 10 plants of each variety. All colour measurements were made using the 2001 Royal Horticultural Society (RHS) Colour chart.

Comparison tables for 'Bulk' with reference variety 'DVPPinky'

Leaf blade length (cm)

  'Bulk' 'DVPPinky'
mean 7.4 9.6
std. deviation 0.71 0.41

Inflorescence width (cm)

  'Bulk' 'DVPPinky'
mean 12.3 9.7
std. deviation 0.99 1.25

Large calyx colour (RHS)

  'Bulk' 'DVPPinky'
at maturity 64D-63B 54A

Click on image for larger view
Hydrangea: 'Bulk' (left) with reference variety 'DVPPinky' (right)

Click on image for larger view
Hydrangea: 'Bulk' (left) with reference variety 'DVPPinky' (right)

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