Hydrangea Section Macrophyllae Cultivars A

'AB Green Shadow'

Flowers quite a deep green on opening, rather than the usual creamy tone, maturing to dark red-pink before ageing green. Compact habit, height under 1 m. A unique floral effect; recommended for pot culture but no real open-garden credentials. Introduced 2000 by Van Bergen/Hofstede, the Netherlands. Protected by European Plant Breeders’ Rights. (Church 2007; van Gelderen & van Gelderen 2004; Royal Horticultural Society 2024; Association Shamrock 2022)

Flowers of Hydrangea 'AB Green Shadow' pass through diverse shades of green and red during their lives (East Ruston Old Vicarage, Norfolk, UK; 19 October 2024). Image Julian Sutton.

'Adria'

Flowers with entire sepals, blue/purplish/pink but particularly attractive when blue; can flower well in colder areas. Compact habit, sometimes spreading, very suitable for pots. Introduced 1957 by August Steiniger, Germany (Boebel 2011; Church 2007; van Gelderen & van Gelderen 2004; Association Shamrock 2022).

'After Midnight'

Flowers purplish / deep pink, in large heads. Leaves dark green, stems red, rather resembling ‘Preziosa’ but with larger heads. Height to around 1.2 m; excellent hardiness in colder areas thanks to genetic input from H. serrata. A seedling of ‘Preziosa’ from the University of Georgia breeding programme named by Mark Griffith and Rick Crowder before 2010, although rejected by Michael Dirr on Cercospora susceptibility, less of a problem away from the American Southeast. Marketed in North America by Greenleaf Nursery Co. under the Garden Debut® brand (Boebel 2018; Dirr 2021; Garden Debut 2024; Association Shamrock 2022). H. ‘Jong02’ AFTER MIDNIGHT, marketed in Europe, is an entirely different plant with purple-black leaves, although online nursery descriptions in Europe sometimes garble the two.

'Agnes Pavelli'

Flowers with entire sepals, pure white, ageing to green in shade, but to red – sometimes vibrantly so – in full sun; more tolerant of full sun than many whites. Leaves strongly serrate. Height to about 1.5 m. Origin unknown, probably French. Largely forgotten in Europe but mainstream in Australia and New Zealand, probably thanks to its tolerance of bright light. (Church 2007; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

'Agrihydradrie'

Flowers tending to bright red, in large heads. Compact, well-branched habit; marketed as suiting pot culture. Selected 2003 by Art Niels of Agriom BV, the Netherlands; protected by US Plant Patent 19,726 and European Plant Breeders’ Rights; widely marketed at the time of writing. (Google Patents 2024; Pépinières Minier 2024)

'Albrechtsburg'

Flowers opening through cream to pink, not readily blueing, with conspicuously toothed sepals. Height 1 m or more. Introduced 1983 by the Nieschütz breeding company, Germany. Maurice Foster (Kent, UK) rates it one of the very best pink mopheads. (Foster 2023; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

Hydrangea 'Albrechtsburg': sterile flowers have conspicuously toothed sepals, opening cream and maturing pink. Image Maurice Foster.

Mature flowers of Hydrangea 'Albrechtsburg': this variety does not 'blue' readily. Image Maurice Foster.

'All Summer Beauty'

Flowers blue / pink, remontant. Leaves glossy green; height about 1.5 m. An otherwise average mophead made special by its hardiness and remontancy. It survives and flowers in USDA Zone 5 or even 4 gardens, and gives a succession of flowers not only on lateral shoots but also on the current year’s shoots coming from the base (‘new wood’). ‘Bailmer’ (=ENDLESS SUMMER®), as well as ‘Dooley’ and ‘Semperflorens’ (not described here), are extremely similar. They may, at the very least, share a common genetic origin (Boebel 2011; Church 2007). According to the International Register (Association Shamrock 2022) ‘Semperflorens’ is the earliest of these names, a plant imported under that latinized name before 1980 from Japan, where it was being sold under that name by a construction company. ‘Grows like topsy!’ (S. Miller pers.comm. 2023).

Hydrangea 'All Summer Beauty', a remontant but otherwise ordinary mophead (Heronswood Garden, WA, United States; 20 July 2018). Image Ross Bayton.

Ageing flowers in Hydrangea 'All Summer Beauty' (private garden, South Devon, UK; 2 November 2024). Image Tom Christian.

One of the early remontant cultivars, Hydrangea 'All Summer Beauty' will flower on new wood when cut to the base in winter (private garden, Argyll & Bute, UK; 22 August 2023). Image Julian Sutton.

'Alpenglühen'

Flowers bright red-pink, apparently never blueing although sometimes taking on ‘plummy’ tones. Leaves glossy dark green; height to about 1.25 m. Introduced 1950 by Brügger, Germany. A significant parent of cultivars. (Church 2007; Foster 2023; van Gelderen & van Gelderen 2004; Association Shamrock 2022; R. Pitts pers. comm. 2023)

Autumn tints in Hydrangea 'Alpenglühen', in a garden where the fresh flowers are often, but not always, plummy rather than pink (Avenue Cottage, Ashprington, Devon, UK; 17 October 2023). Image Julian Sutton.

Hydrangea 'Alpenglühen', a classic pink mophead (Darley Park, Derby, UK; 28 August 2023). Image Julian Sutton.

'Altona'

Flowers deep blue / deep pink, in large, dense heads, turning red in autumn; floriferous. Height 1.5–2 m, tolerant of sun but perhaps best in light shade (Bean 1981; Foster 2023; van Gelderen & van Gelderen 2004). ‘One of the best varieties for windy or coastal gardens’ (Church 2007). Flowering reasonable in unfavourable upstate New York (Boebel 2011). One of the classic mopheads, introduced 1931 by Heinrich Schadendorf, Germany, along with very similar sister seedlings ‘Europa’ and ‘Hamburg’ (Association Shamrock 2022), presumably named for the Hamburg suburb.

Hydrangea 'Altona', a classic mophead with richly coloured, dense heads (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

Hydrangea 'Altona' at an early stage of flowering (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

'Amagi-amacha'

Sterile and fertile flowers white, in small inflorescences; very narrow leaves with pale, often yellow-green midrib; height to 1 m, often much less. A wild find on the Izu Peninsula, Honshu, by botanist Tomitaro Makino in about 1925. A much-loved cultivar among enthusiasts: ‘though a hardy and durable selection, it appears so delicate that one almost wants to whisper in its presence’ (Hydrangea Derby 2024); ‘all light and air, a delicate spread of lace’ (Foster 2023).

Hydrangea serrata 'Amagi-amacha', a beautiful wild find (29 June 2022). Image Maurice Foster.

Hydrangea serrata 'Amagi-amacha', a lovely, delicate-looking cultivar (Windcliff garden, WA, United States; 27 June 2023). Image John Grimshaw.

'Amethyst'

Flowers with serrate sepals, pale lilac / shell pink, not readily blueing; a double, with numbers of small extra sepals as an irregular central whorl in each sterile flower; the flowers are tightly packed before the small, flattened head is fully expanded, giving a distinctive ruffled look in combination with the doubling and serrations. Late flowering, but very satisfactory even in upstate New York when Tim Boebel’s (2011) method is used. Compact, height 1 m or so. A seedling of ‘Europa’ selected 1938 by Michael Haworth-Booth, UK (Church 2007; Haworth-Booth 1984; Lawson-Hall & Rothera 1995; van Gelderen & van Gelderen 2004; Association Shamrock 2022). Note the potential confusion with H. quercifolia ‘Amethyst’, a more recently published name.

'Ami Pasquier'

Flowers with rounded, overlapping sepals, purplish-red / crimson, not blueing readily, in small, dense heads. Stems dark, height to 1.5 m; good autumn leaf colour possible. A seedling of ‘Maréchal Foch’ introduced 1930 by Émile Moullière, France. ‘Westfalen’ is similar (Church 2007; Lawson-Hall & Rothera 1995; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

Hydrangea 'Ami Pasquier' tends to the pink end of the colour range (16 July 2021). Image Maurice Foster.

Hydrangea 'Ami Pasquier' as close to blue as it gets (30 July 2022). Image Maurice Foster.

'Arthur Billard'

Flowers with entire sepals, deep violet-blue / crimson, readily changing colour with aluminium availability and especially valued as an intense red. Fairly compact, and suitable for pot culture. Introduced 1931 by Émile Mouillère, France, the name commemorating an early 20th century French Begonia breeder and nurseryman; at one time an important cultivar for forcing (Church 2007; Haworth-Booth 1984; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

'Aya-ezo-yae'

Sterile flowers double, with many elliptic sepals, blue-tinged white/pale pink though tending towards pink, on long pedicels; fertile flowers few or none, but the inflorescence is airy and open, not a classic mophead; long flowering season. Sturdy, upright habit, to 1 m in height. ‘An outstanding cultivar’ (Foster 2023). A wild find in the Yamanaka region of Honshu; Aya is the name of the discoverer’s granddaughter. (Foster 2023; Sous Un Arbre Perché 2024; Association Shamrock 2022)

Hydrangea serrata 'Aya-ezo-yae' has few fertile flowers but is not a classic mophead, a lovely, airy plant for a shady spot (White House Farm, Kent, UK; 12 July 2024). Image Julian Sutton.

Hydrangea serrata 'Aya-ezo-yae' has double flowers with elliptic sepals tending towards pale pink (White House Farm, Kent, UK; 12 July 2024). Image Julian Sutton.

'Ayesha'

Flowers quite small with thick, strongly concave, spoon-shaped sepals, initially cream but maturing light blue/lilac/pink, densely packed; lightly scented. The floral effect has been called lilac-like (Bean 1981) and unique, although a few similar mutants are known. Height 1.5–2 m; tolerant of sun and coastal exposure but not free-flowering in colder areas. Origin Japanese, presumed to be a branch sport on ‘Joseph Banks’ or similar, because reverted branches are often seen, from which stable, fully reverted plants can be grown from cuttings. Single part-reverted inflorescences occur only rarely (J. Grimshaw pers. comm. 2024). ‘Uzu Ajisai’ might be an earlier Japanese name. (Boebel 2011; Church 2007; Hydrangea Derby 2024; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

Hydrangea 'Ayesha' often throws branch sports with conventional, flat sepals (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

A rare example of a partially reverted inflorescence in Hydrangea 'Ayesha' (Breezy Knees Garden, N Yorkshire, UK; 28 July 2024). Image John Grimshaw.

Sterile flowers of Hydrangea 'Ayesha' have distinctive cupped sepals (Coleton Fishacre, Devon, UK; 5 August 2023). Image Julian Sutton.

Hydrangea 'Ayesha' with pink flowers (Dunster Castle, Somerset, UK; 21 July 2023). Image Tom Christian.

Hydrangea 'Ayesha' flowers in blue mode (Coleton Fishacre, Devon, UK; 5 August 2023). Image Julian Sutton.

Hydrangea 'Ayesha' suits gardens in milder areas (Dunster Castle, Somerset, UK; 21 July 2023). Image Tom Christian.