<i>Phlox </i>plant named ‘Backlight’

Abstract

A unique cultivar of Tall Phlox plant named ‘Backlight’ characterized by vigorous, dense, upright, multi-stemmed, winter-hardy habit with dark-green, lanceolate leaves. Flowering begins in late-July and continuing for up to five weeks in cooler weather conditions, on heavily-branched peduncles and completely cover the top of the plant in peak season. Petals are white with a pale yellow eye. The new plant shows excellent powdery mildew resistance. The new plant is especially suitable for a cut flower, for the landscape as a potted plant and in the garden as a specimen or en masse.

Claims

1. A new and distinct cultivar of Tall Phlox, Phlox plant named ‘Backlight’, as herein described and illustrated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The photographs of the new plant demonstrate the unique traits of Phlox ‘Backlight’ and the overall appearance of the plant at two-years-old growing in a full-sun display garden in Zeeland, Mich. The colors in the drawings are as accurate as reasonably possible with color reproductions. Variation in ambient light spectrum, source and direction may cause the appearance of minor variation in color.

(2) FIG. 1 shows a landscape habit view of the new plant in peak flower.

(3) FIG. 2 shows a close-up of the flowers and buds.

DETAILED BOTANICAL DESCRIPTION

(4) The following descriptions and color references are based on the 2015 edition of The Royal Horticultural Society Colour Chart except where common dictionary terms are used. Phlox ‘Backlight’ has not been observed under all possible environments. The phenotype may vary slightly with different growing environments such as temperature, light, fertility, soil pH, moisture and maturity levels, but without any change in the genotype. The following observations and size descriptions are based on two-year-old plants in a partially shaded greenhouse or a full-sun trial garden of a wholesale perennial nursery in Zeeland, Mich. with supplemental fertilizer and water as needed. Botanical classification: Phlox paniculata; Parentage: Female or seed parent is Phlox paniculata ‘Dick Weaver’; male or pollen parent is the proprietary hybrid known by the breeder name 14-SP-PHLO-320; Plant habit: Winter-hardy, evergreen herbaceous perennial; dense, producing about 18 stiff, upright stems; flowering to about 77.0 cm tall and 60.0 cm wide; Propagation: Stem cuttings; rooting in about 3 weeks; Time to produce finished crop in 3.8 liter pots: About 8 to 10 weeks; vigorous; Root: Fibrous and freely branching; color creamy white to tan depending on soil type; Leaves: Simple; opposite; lanceolate; apex narrowly acute; base attenuate; margin micro-dentate; glabrous both adaxial and abaxial; to about 11.5 cm long by about 3.4 cm wide, average about 10.2 cm long and 3.2 cm wide; Leaf color: Adaxial expanding nearest RHS 144A and abaxial expanding between RHS 145A and RHS 146D; mature adaxial between RHS 139A and RHS NN137A and mature abaxial between RHS 147B and RHS 147C; lacking anthocyanin expression; Foliage fragrance: None detected; Veins: Pinnate; convergent near leaf margin; glabrous adaxial and abaxial, midrib about 1.5 mm wide at base; slightly impressed adaxial and costate abaxial; Vein color: Adaxial midrib and primary veins nearest RHS N148B; abaxial midrib nearest RHS 145C proximally, and distal midrib and primary veins nearest RHS 146D and secondary veins nearest RHS NN137B; Petiole: Flattened; glabrous adaxial and abaxial; about 2.0 mm long and 4.0 mm wide; Petiole color: Nearest RHS 145A adaxial and nearest RHS 146D abaxial; Stems: Cylindrical; stiff; upright; glabrous, limited branching below flowers; to about 77.0 cm long and 9.0 mm diameter near base, average about 69 cm long and 8.0 mm diameter at base; Stem color: Proximal portion between RHS 146C and RHS 147C with raised longitudinally striated ridges of between RHS 199D and RHS 161B; distal portion nearest RHS 146C; lacking anthocyanin expression; Nodes: 11 nodes before flowers; average about 4.3 cm apart, greater proximally; Node color: Color nearest RHS 146D; Inflorescence: Upright; with 14 branched nodes; densely flowering in about the upper 26.0 cm and about 25.0 cm wide; about 600 to 900 flowers per branched stem; Flowers: Perfect; salverform; mostly flat faced; about 24.0 mm across face and 23.0 mm long; with fused corolla tube about 22.0 mm long and 4.0 mm diameter near face and 2.0 mm diameter at base; attitude upright to outwardly; Flower longevity: About 5 days on plant; self-cleaning; Flower fragrance: Lightly sweet; Buds one to two days prior to opening: Narrowly clavate to narrowly obovoid; acute apex with rounded base; petals implicate; abaxial corolla tube puberulent, bulb and calyx glabrous; Bud size: About 19.0 mm long and 5.5 mm diameter in terminal bulb portion, and 4.0 mm diameter in corolla tube proximal bulb and base of corolla tube nearest RHS 2.5 mm diameter; Bud color: Exposed petal bulb portion nearest RHS NN155A; corolla tube portion nearest RHS 145C; calyx nearest RHS 146B with white translucent margins nearest RHS NN155D; Petals: Typically five, rarely six; consisting of limb and basal claw fused into corolla tube; limb obdeltoid to nearly orbicular; apex rounded, margin entire; limbs imbricate about 40 percent; limb glabrous adaxial and abaxial, adaxial corolla tube pubescent in proximal 4 to 6 mm and glabrous distally, abaxial corolla tube puberulent; with no anthocyanins; Petal size: Limb about 10.0 mm long and 12.0 mm wide near middle; tube about 22.0 mm long and 4.0 mm diameter near face and 3.0 mm diameter near base; Petal color upon first opening: Adaxial.—Limb nearest RHS NN155D, with center eye between RHS 2D and RHS NN155D; distal 12.0 mm of corolla tube between RHS 2D and RHS NN155D, proximal 10.0 mm of corolla tube portion nearest RHS 145D. Abaxial.—Limb nearest RHS NN155D, corolla tube between RHS 145C and RHS 150D. Petal color upon maturity: Adaxial.—Limb nearest RHS NN155D, with center eye between RHS 2D and RHS NN155D; distal 12.0 mm of corolla tube between RHS 2D and RHS NN155D, proximal 10.0 mm of corolla tube portion nearest RHS 145D. Abaxial.—Limb nearest RHS NN155D, corolla tube between RHS 145C and RHS 150D. Androecium: Typically five; Filaments.—Typically five, adnate to inner corolla to various heights about 12.0 mm to 17.0 mm from base; free in the distal 0.5 mm and 0.2 mm in diameter; color nearest RHS 150D. Anther.—Five; oblong ellipsoidal; basifixed; longitudinal; about 4.0 mm long by 1.0 mm wide; color nearest RHS 11D. Pollen.—Nearly microscopic; color nearest RHS 18C. Gynoecium: One pistil per flower; 20.5 mm long; Style.—Cylindrical; about 17.0 mm long and 0.3 mm diameter when flower is mature; persistent after flower abscission; color nearest RHS 145C. Stigma.—Typically trifid in proximal 1.0 mm long; about 0.3 mm diameter; color nearest RHS 11C. Ovary.—Inferior; turbinate; glabrous; lustrous; acute apex and truncate base; about 2.5 mm long and 1.2 mm diameter at base; color nearest RHS 146B. Calyx: Campanulate; about 6.0 mm long and 3.0 mm across at apex; Sepals: Typically five, rarely six; linear; adaxial slightly lustrous and matte abaxial; narrowly acute apex, fused in basal 4.0 mm, free in distal 3.0 mm; margin entire; individually about 7.0 mm long and 1.5 mm wide at fusion; Sepal color: Adaxial between RHS 146B and RHS 141A with transparent to translucent margin about 0.5 mm wide; abaxial between RHS 146B and RHS 141A with a transparent to translucent margin; margin adaxial and abaxial nearest RHS NN155D; no anthocyanin; Peduncle: Glabrous; stiff; upright; cylindrical; highly branched; to 26.0 cm long and 5.0 mm diameter; with up to 14 branches at about a 50 degree angle above horizontal, branches to about 2.5 mm diameter at base and 18.0 cm long; Peduncle color: Nearest RHS 146C; Pedicel: Cylindrical; glabrous; flexible; upright to outwardly; to about 3.0 mm long and 0.7 mm diameter; Pedicel color: Between RHS 138A and RHS 146D; Fruit: Dehiscent, few-seeded capsule, typically 1 seed; fecundity low; flattened ellipsoidal; glabrous; to about 4.5 mm long and 2.5 mm diameter in middle; color at maturity nearest RHS N200A; Seeds: Flattened ellipsoidal; glabrous; to 5.0 mm long, 3.0 mm across and 1.5 mm thick; color nearest RHS 202A; Hardiness and culture: The new plant grows best with full sun, light moisture and deep drainage; hardy to at least from USDA zone 3 through 8. Disease and pest resistance: Phlox ‘Backlight’ demonstrates excellent powdery mildew (Erysiphe cichoracearum) resistance under conditions that would normally show symptoms. No nest resistance beyond that common for Phlox has been observed.