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Hydrangea, macrophylla 'Merritt's Supreme'

Magnificent flowers! A must for your butterfly garden!
Hydrangea macrophylla, 'Merritt's Supreme' is a mophead-like cultivar. Merritt's Supreme is a tidy little hydrangea measuring in at a compact 4' high and as wide. This smaller sized plant blooms a beautiful rose pink to purple in a high acid soil. It features sterile florets in huge spherical clusters. Flowers bloom in early July for up to two months. The flower heads stay in perfect condition turning to green, red, or purple autumnal tints.

Hydrangeas are among the showiest of all the flowering shrubs, and the 'Merritt's Supreme' Hydrangea is magnificent. Spectacular in any landscape design, this dazzling shrub is versatile, vigorous and easy to cultivate. The flower color of the 'Merritt's Supreme' hydrangea depends on the acidity level of the soil. The flower color of violet/blue or rose/pink hydrangea varieties often varies depending on soil pH. Plants grown in moderately acidic soil produce bluer flowers, while those planted in neutral to slightly alkaline soil produce pinker flowers.

Plant Details +

Botanical Hydrangea macrophylla 'Merritt's Supreme'
Common Name Bigleaf Hydrangea
Family Hydrangeaceae (hydrangea Family)
Height 3-4'
Spacing 3-4'
Hardiness Zones 5-9
Exposure Partial Shade. Hydrangeas benefit from some shade in the middle of the afternoon, especially in hotter regions.
Foliage Lustrous Rich Green Leaves
Flower Violet/Blue in acid soil; Rose/Pink in alkaline soil.
Bloomtime Mid-Summer to Early Fall

General Information +

General Characteristics: Hydrangea macrophylla, commonly called bigleaf hydrangea, is a deciduous shrub with a rounded habit that typically grows 3-4' tall and as wide unless damaged by harsh winters or pruned smaller. It generally features serrate, obovate to elliptic, dark green leaves (4-8" long) and large clusters of long-blooming summer flowers in either lacecap form (flattened flower clusters of small fertile florets with scattered showy sterile florets often forming a marginal ring) or mophead form (globose flower clusters of mostly showy sterile florets). Best grown in rich, medium moisture, well-drained soils in part shade. Tolerates full sun only if grown in consistently moist soils. Soil pH affects the flower color (blue in highly acidic soils and lilac to pink in slightly acidic to alkaline soils). Add aluminum sulfate to the soil to make the flowers bluer or add lime to the soil to make the flowers pinker. Begin soil treatments well in advance of flowering, as in late autumn or early spring. Plants generally need little pruning. If needed, prune immediately after flowering by cutting back flowering stems to a pair of healthy buds. Prune out weak or winter-damaged stems in late winter/early spring. Best to mulch plants year-round with 3" of shredded bark, peat or compost. Winter hardy to USDA Zone 5. For added protection, however, plants grown in USDA Zone 5 should be sited in sheltered locations and given additional winter protection, as needed, for the purposes of minimizing the risk of loss of significant numbers of flower buds or possible die-back to the ground in an extremely harsh winter. A burlap wrap of stems or circle of chicken wire filled with leaves or straw to 8-12" are time-consuming and visually unattractive landscape options, but can be effective. Regardless of protective measures taken, bigleaf hydrangeas simply will not bloom (or will bloom poorly) in some years because of a variety of winter occurrences beyond the control of the gardener (e.g. low temperatures, sudden wide temperature fluctuations, icy conditions, late frosts). This hydrangea grows best in fertile, well-drained soils. They are not very drought tolerant and should be watered regularly during dry periods. The hydrangea should be placed in partial shade in areas that have overly hot summers. Group or mass in a sheltered location of the shrub border. Great cut flower. Also a good specimen or accent for protected locations near homes or patios.

Planting/Care Instructions +

Planting Instructions: Merritt's Supreme' should be planted in moist, rich, well-drained soil. Dig a hole large enough to encompass the roots without bending or circling. Set the plant in place so the crown (part of the plant where the root meets the stem) is about 1-2 inches below the soil surface. When planting your 'Merritt's Supreme', the crown (where the stem meets the roots) should be placed just below ground level. Planting deeper can cause the roots to rot. Cover with soil to the original soil surface and water thoroughly. Once the shrub is placed in the hole, tamp the soil down around it and water. It is a good idea to mulch your hydrangea to help the soil to retain moisture. It should also be fertilized with a light fertilizer in March, May, and July. Hydrangeas require moderate watering during the growing season.

Pests or Diseases: No serious insect or disease problems. Some susceptibility to bud blight, bacterial wilt, leaf spot and mildew. Aphids are occasional visitors.