Tor Gold

Spirea

Variety Description

Variety used for comparison: 'Tor'

Summary: The plants of 'Tor Gold' have thinner shoots and smaller diameter inflorescences than the plants of 'Tor'. When newly open, the upper side of the young leaf blade of 'Tor Gold' is yellow to green with a light reddish blush at the margin whereas the young leaf blade of 'Tor' is green with a light reddish blush at the margin. When fully open, the upper side of the leaf blade of 'Tor Gold' is green brown with dark green at the base and lighter green overcolour while the leaf blade of 'Tor' is brown green.

Description:

PLANT: bushy rounded growth habit, medium branching density, dense foliage
YOUNG SHOOT: light green, strong intensity of anthocyanin colouration towards distal end
SHOOT: reddish brown, absent or very sparse pubescence, angular in cross-section, thin

LEAF BUD: absent or very sparse pubescence, rounded apex, very short, very narrow
LEAF BLADE: upper side is yellow to green with light reddish blush at margin when newly open, upper side is green brown (RHS 153C-D) with dark green (RHS 143B) at base and dark green (RHS 143C) overcolour when fully open, broad elliptic shape, obtuse apex, obtuse base, sparse pubescence on upper side, absent or very sparse pubescence on lower side, absent or very weak glaucosity on lower side, absent or very weak glaucosity on veins on lower side, weak rugosity
LEAF BLADE MARGIN: dentate shape with crenate shape on distal third only, absent or very weak undulation, absent or very sparse pubescence
PETIOLE: present

FLOWERING: occurring after leaf emergence, begins mid-season for a medium length of time
INFLORESCENCE: no peduncle, compound corymb type, many florets
CALYX: absent or very sparse pubescence
COROLLA: arrangement of petals touching to overlapping
PETAL: white (RHS NN155A) on upper side, absent or very weak reflexing of margin, absent or very weak to weak undulation
STAMEN: longer in relation to length of petals
ANTHER: yellow white

Origin & Breeding History: 'Tor Gold' was discovered in June 2006 and developed by the breeder, Ton Stolwijk, in Hazerwoude-Dorp, Netherlands. It was discovered as a naturally occurring branch mutation of the Spiraea betulifolia variety 'Tor'. 'Tor Gold' was selected for its yellow foliage colour, orange to purple red foliage colour in autumn, good plant health and plant hardiness. Asexual reproduction of 'Tor Gold' by softwood cuttings was first conducted in June 2006 in Hazerwoude-Dorp, Netherlands.

Tests & Trials: The comparative trial of 'Tor Gold' was conducted as an outdoor irrigated container trial during the spring of 2014 at BioFlora Inc. in St. Thomas, Ontario. It included a total of 15 shrubs each of the candidate and reference variety. All shrubs were grown from rooted cuttings and transplanted into 13.5 litre containers on June 14, 2013. Observations and measurements were taken from 10 shrubs or parts of shrubs of each variety on June 10, 2014. All colour determinations were made using the 2007 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'Tor Gold' with reference variety 'Tor'

Colour of upper side of leaf blade (RHS)

Inflorescence diameter (cm)

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Spirea: 'Tor Gold' (left) with reference variety 'Tor' (right)

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Spirea: 'Tor Gold' (left) with reference variety 'Tor' (right)