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Hydrangea serrata ‘Diadem’

Mountain Hydrangea 'Diadem', Diadem Mountain Hydrangea

AGM Award
Hydrangea serrata 'Diadem', Mountain Hydrangea 'Diadem', Diadem Mountain Hydrangea, Pink Flowers, Pink Hydrangea

Flowering before any other hydrangea, Hydrangea serrata ‘Diadem’ is a compact, spreading, deciduous shrub laden with delicate lacecap flowers, up to 6 in. across (15 cm), in early summer. The flower heads are composed of large, showy sterile sepals radiating around a central cluster of tiny fertile florets. Depending on the soil pH, the florets are pale pink or light blue. The profuse blossoms are beautifully framed by the foliage of narrowly ovate, pointed, yellow-green leaves. ‘Diadem’ is an outstanding landscape shrub ideal for small gardens.

  • Winner of the prestigious Award of Garden Merit of the Royal Horticultural Society
  • This deciduous shrub has a round, bushy habit, typically growing up to 3 ft. tall and wide (90 cm)
  • A full sun or part shade lover, it is best grown in rich, medium moisture, well-drained soils. Tolerant of sun if the soil remains moist.
  • No serious pest or disease issues. Watch for aphids, capsid bug, hydrangea scale and vine weevil.
  • Perfect from foundation plantings to container plantings. Massed in a sheltered location or as an accent plant.
  • To change the color of your Hydrangea, add aluminum sulfate to the soil to make the flowers bluer or add lime to the soil to make them pinker. Treatment should occur ahead of time (late fall or early spring)
  • This beautiful deciduous shrub should be pruned after flowering by cutting back the stems to a pair of healthy buds. Prune out weak or winter-damaged stems in early spring.
  • Hydrangea serrata species is native to Japan and Korea.
  • May cause mild stomach ache if ingested, contact with foliage may aggravate skin allergies.
  • Toxic to dogs, toxic to cats, toxic to horses.

Hydrangea: Plant Care and Growing Guide


Hydrangea care: Cultivating these beautiful flowers requires attention and finesse to thrive. Here are some tips on how to plant and grow hydrangea successfully.

Requirements

Hardiness 6 - 9
Heat Zones 5 - 9
Climate Zones 3, 3B, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1
Plant Type Shrubs
Plant Family Hydrangeaceae
Genus Hydrangea
Common names Mountain Hydrangea, Hydrangea
Exposure Full Sun, Partial Sun
Season of Interest Summer (Early, Mid, Late),
Height 2' - 3' (60cm - 90cm)
Spread 2' - 3' (60cm - 90cm)
Spacing 48" (120cm)
Maintenance Low
Water Needs Average
Soil Type Clay, Loam, Sand
Soil pH Acid, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Cut Flowers, Plant of Merit, Showy
Garden Uses Beds And Borders, Patio And Containers, Small Gardens, Wall-Side Borders
Garden Styles Traditional Garden, Informal and Cottage, Coastal Garden, City and Courtyard
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Alternative Plants to Consider

Hydrangea macrophylla ‘Kardinal Violet’
Hydrangea macrophylla Wedding Gown™
Hydrangea serrata Tuff Stuff™ (Mountain Hydrangea)
Hydrangea macrophylla Cityline® Venice
Hydrangea macrophylla Cityline® Vienna
Hydrangea macrophylla ‘Blue Heaven’

Recommended Companion Plants

Acer palmatum ‘Beni-Maiko’ (Japanese Maple)
Hosta ‘Wide Brim’ (Plantain Lily)
Actaea simplex (Atropurpurea Group) ‘Brunette’ (Baneberry)

Find In One of Our Guides or Gardens

Pure White Flowers for a Touch of Elegance in Your Garden
Stunning Blue Flowers to Enhance Your Garden’s Beauty
Choosing Your Ideal Hedge: A Guide to Top Shrubs for Any Garden
Add a Splash of Color: Perfect Flowering Shrubs for Small Gardens
35 Flowering Shrubs That Thrive in Full Sun
40 Beautiful Native Shrubs for Shade
Hydrangea serrata (Mountain Hydrangea)
Hydrangea macrophylla (Bigleaf Hydrangea)
Hydrangea Types – Which one is yours?
Hydrangea paniculata (Panicle Hydrangea)
Hydrangea arborescens (Smooth Hydrangea)
Hydrangea quercifolia (Oak Leaf Hydrangea)
Beautiful Hydrangeas for the Pacific Northwest Region
Beautiful Hydrangeas for the Mid-Atlantic Region
Beautiful Hydrangeas for New England
Beautiful Hydrangeas for the Coastal South Region
Beautiful Hydrangeas for the Lower South Region
Beautiful Hydrangeas for the Middle South Region
Beautiful Hydrangeas for the Upper South Region
Plants with Purple Flowers to Add Charm to Your Garden
Plants with Pink Flowers to Add Romance to Your Garden
Hydrangea: Plant Care and Growing Guide
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
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Requirements

Hardiness 6 - 9
Heat Zones 5 - 9
Climate Zones 3, 3B, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1
Plant Type Shrubs
Plant Family Hydrangeaceae
Genus Hydrangea
Common names Mountain Hydrangea, Hydrangea
Exposure Full Sun, Partial Sun
Season of Interest Summer (Early, Mid, Late),
Height 2' - 3' (60cm - 90cm)
Spread 2' - 3' (60cm - 90cm)
Spacing 48" (120cm)
Maintenance Low
Water Needs Average
Soil Type Clay, Loam, Sand
Soil pH Acid, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Cut Flowers, Plant of Merit, Showy
Garden Uses Beds And Borders, Patio And Containers, Small Gardens, Wall-Side Borders
Garden Styles Traditional Garden, Informal and Cottage, Coastal Garden, City and Courtyard
How Many Plants
Do I Need?
Explore Great Plant Combination Ideas
Hydrangea
Guides with
Hydrangea
Not sure which Hydrangea to pick?
Compare Now

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