<i>Hydrangea </i>plant named ‘GRHP12’

Abstract

A new cultivar of Hydrangea paniculata plant named ‘GRHP12’ that is characterized by its flower panicles that change in color from lime green and white to green and pink to dark cherry pink as they mature, its well-branched plant habit with sturdy stems, its floriferous blooming habit, its dense and sturdy flower panicles, and its large flower panicles with rounded, large sepals.

Claims

1. A new and distinct cultivar of Hydrangea plant named ‘GRHP12’ substantially as herein illustrated and described.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying color photographs illustrate the overall appearance and distinct characteristics of the new Hydrangea. The photographs were taken of three-year-old plants of ‘GRHP12’ grown outdoors in a trial field in Valkenburg, The Netherlands.

(2) The photograph in FIG. 1 provides a view of several plants of ‘GRHP12’ (center) in bloom in fall.

(3) The photograph in FIG. 2 provides a close-up view of an inflorescence of ‘GRHP12’ in fall.

(4) The photograph in FIG. 3 provides a close-up view of an inflorescence of ‘GRHP12’ in late summer.

(5) The colors in the photographs are as close as possible with the photographic and printing technology utilized and the color values cited in the detailed botanical description accurately describe the colors of the new Hydrangea.

BOTANICAL DESCRIPTION OF THE PLANT

(6) The following is a detailed description of 2.5-year-old plants of ‘GRHP12’ as grown outdoors in a trial garden in Vorden, The Netherlands. The phenotype of the new cultivar may vary with variations in environmental, climatic, and cultural conditions, as it has not been tested under all possible environmental conditions. The color determination is in accordance with The 2015 Colour Chart of The Royal Horticultural Society, London, England, except where general color terms of ordinary dictionary significance are used. General description: Blooming period.—Mid-summer through autumn in The Netherlands. Plant type.—Deciduous shrub, panicle type Hydrangea. Plant habit.—Medium size, dense, and upright. Height and spread.—Reaches 100 to 120 cm in height and spread ion the landscape. Hardiness.—At least in U.S.D.A. Zones 4 to 9. Diseases and pests.—No susceptibility and resistance to diseases or pests has been observed. Root description.—Fibrous, NN155A and 164A in color. Propagation.—Stem cuttings. Root development.—6 to 8 weeks for root initiation with a finished plant produced in in a P9 container in about 12 months from a rooted cutting. Growth rate and vigor.—Moderate. Stem description: Stem shape.—Rounded. Stem strength.—Strong. Stem color.—Young; 145B, mature; 200C, old bark; N199B. Stem size.—Average of 66 cm in length (excluding inflorescence) and 8 mm in diameter. Stem surface.—Stems are slightly pubescent and covered with lenticels an average of 2 mm in length, mature bark is mostly smooth and lacks fasciation. Internode length.—An average of 5 cm. Branching.—Freely branching with an average of 15 lateral branches, sturdy. Foliage description: Leaf shape.—Ovate. Leaf arrangement.—Opposite. Leaf division.—Simple. Leaf base.—Obtuse. Leaf apex.—Acute. Leaf margins.—Serrate. Leaf venation.—Pinnate, color; upper surface 145B, lower surface 145B to 145C. Leaf size.—An average of 15.2 cm in length and 7.3 cm in width. Leaf attachment.—Petiolate. Leaf surface.—Both surfaces; matte, and pubescent. Leaf color.—Young upper surface; 137A, young lower surface 137C, mature upper surface 137B, mature lower surface 137C to 137D. Petioles.—An average of 2.1 mm in length and 3 mm in diameter, both surfaces matte and slightly pubescent, color 145D and 187B to 187C. Inflorescence description: Inflorescence type.—Terminal conical panicle, comprised of sterile and fertile flowers. Lastingness of inflorescence.—Sterile flowers; persistent for an average of 6 weeks, fertile flowers; self-cleaning, an average of 5 days. Inflorescence number.—One per lateral stem. Inflorescence size.—An average of 24 cm in height and 20 cm in diameter. Flower number.—An average of 300 sterile flowers and 150 fertile flowers per panicle. Flower fragrance.—None. Flower size.—Sterile flowers; up to 5 cm in diameter and 1.2 m in depth, fertile flowers; an average of 5 mm in diameter and 3 mm in depth. Flower type.—Rotate. Flower buds.—Sterile flowers; an average of 2 mm in length and diameter, round in shape, 145D, fertile flowers; an average of 3 mm in length and diameter, ovoid in shape, 145C to 145D in color. Petals.—Sterile flowers; petals do not open and remain in bud stage, fertile flowers; 5, rotate and cruciform in shape, ovate in shape, acute apex, cuneate base, entire margins, average of 3 mm in length and 1.5 mm in width, both surfaces glabrous and slightly glossy, color; when opening and fully open upper and lower surface NN155D. Peduncles.—Primary peduncles; strong, flattened oval in shape, an average of 3 cm in length and 2 mm in width. secondary peduncles 2 cm in length and 2 mm in width, 145C to 145D in color, surface is matte and pubescent. Pedicels.—Sterile flowers; moderate strength, an average of 1.8 cm in length and 1 mm in width, 145D in color, surface is matte and pubescent, fertile flowers; moderate strength, an average of 2 mm in length, 1 mm in diameter, 145C to 145D in color, surface is matte and slightly pubescent. Sepals.—Sterile flowers; 4 to 5, rotate, elliptic to ovate in shape, obtuse apex, acute base, entire margins, average of 2.2 cm in length and 1.7 cm in width, both surfaces glabrous and matte, color: upper and lower surface when opening; 145B to 145C, upper surface when fully open; 145C to 145D, later in the season sepals change to NN155D and 145D with flushes of 63A, as the sepals mature they start to become 60A to 60B, becoming fully 60A to 60B in autumn, lower surface when fully open; 145C to 145D with 60C to 60D, fertile flowers; 5, rotate, ovate in shape, acute apex, broad cuneate base, entire margins, 2 mm in length, 1 mm in width, both surfaces glabrous and matte, color: when opening and fully open upper and lower surface; NN155D. Reproductive organs: Gynoecium.—Sterile flowers; flowers do not open, fertile flowers; 1 pistil, an average of 2 mm in length, stigma; club-shaped and 157B in color, style; 1 mm in length, NN155D in color, ovary is 157D in color. Androecium.—Sterile flowers; flowers do not open, fertile flowers; stamens; average of 10, filaments; 3 mm in length, NN155D in color, anthers; broad oblong in shape, 1 mm in length, 155D in color, pollen; low to moderate quantity, 156C in color. Fruit and seed.—None observed to date.