Hydrangea Section Macrophyllae Cultivars R

'Rabe'

(City-line Series) Flowers lilac / pink, often with whitish centres, in large heads; late flowering. Very compact; height under 1 m, suitable for pots. For Boebel (2018) in USDA Zone 6, this is a beautiful container plant but a poor bloomer in the open garden. Selected 1994 by Franz-Xaver Rampp, Germany; originally protected by US Plant Patent 10,912 and European Plant Breeders’ Rights (Spring Meadow Nursery 2024; van Gelderen & van Gelderen 2004; Google Patents 2024). It is unclear which cultivar name takes priority.

'Ramis Pictis'

Sterile flowers few, white or pale pink, becoming red-stained over time; fertile flowers blue. Petioles and veins purplish red, especially striking when viewed on young shoots from the side; current years stems range from olive-green spotted purplish-red around the lenticels (hence the cultivar name), to more or less uniformly dark-tinted. Vigorous, to about 1.5 m height. An old Japanese plant brought to Europe by Philipp von Siebold by 1860, probably ‘Akaeda Yama’ (Pépinière AOBA 2024; Sous Un Arbre Perché 2024; van Gelderen & van Gelderen 2004; Association Shamrock 2022; pers. obs. 2023).

Hydrangea serrata 'Ramis Pictis' has striking red petioles and veins (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

Young stems of Hydrangea serrata 'Ramis Pictis' may be olive with red/purple lenticels (hence the name) or more uniformly pigmented (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

Lacecap inflorescences of Hydrangea serrata 'Ramis Pictis' have relatively few sterile flowers (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

'Rapa'

(City-line Series) Flowers tending towards intense red-pink, in large heads. Very compact; height under 1 m, suitable for pots. Selected 1994 by Franz-Xaver Rampp, Germany; originally protected by US Plant Patent 10,906 and European Plant Breeders’ Rights (Royal Horticultural Society 2023; van Gelderen & van Gelderen 2004; Google Patents 2024). It is unclear which cultivar name takes priority.

'Red Angel'

(Black Diamonds Series) Flowers tending to red with small cream centres; stems dark red-brown; leaves flushed bronze when young; height 1–1.5 m. Selected 2008 by Synergy Breeding (Royal Horticultural Society 2023; Association Shamrock 2022).

'Red Emperor'

Flowers purplish-red / vivid crimson, tending strongly towards red; heads neat and rather flattened; late flowering in Europe. Height to 1.5 m. Introduced 1938 by Emil Draps, Belgium. Now rarely seen in Europe but still in the Australian and New Zealand nursery trade (Church 2007; van Gelderen & van Gelderen 2004; Association Shamrock 2022).

Rembrandt® Series

A brand of Dutch nursery Lendert de Vos, marketed in Europe primarily as pot plants (Kwekerij Lendert de Vos 2024). A similar range is sold as the BloomChampion series in North America, through a licencing company in which the de Vos nursery is a partner. We describe ‘Hore0007’ (ROSSO GLORY) and ‘Hore0046’ (VIBRANT VERDE).

'Renate Steiniger'

Flowers blue/purplish/pink, but tending towards blue, in tidy rounded heads; several commentators rate it as one of the very best blue mopheads. Neat and compact, to about 1.25 m in height; good in pots. Introduced 1964 by August Steiniger, Germany. (Church 2007; Foster 2023; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

Purplish autumn tints in Hydrangea 'Renate Steiniger' a good compact cultivar (Avenue Cottage, Ashprington, Devon, UK; 17 October 2023). Image Julian Sutton.

Rendez-vous Series

A range of lacecaps and mopheads bred, produced and marketed primarily in the European pot plant trade by French hydrangea nursery Sicamus (Sicamus 2024). We include ‘French Cancan’ as an example.

'Rheinland'

Flowers with entire sepals, purple/red, strong colours tending to the red. Height 1.5 m or so. Selected 1952 by August Steiniger, Germany. Rarely seen in the nursery trade today, although Church (2007) reckons it ‘still one of the best reds’. (Woodleigh Nursery 2024; van Gelderen & van Gelderen 2004; Association Shamrock 2022)

'Rie05'

(You&Me® Series) Flowers neatly double with broad, overlapping sepals, mid-blue / pink, ageing red; inflorescences dense, held well above the leaves, good for drying though short-stemmed. Compact, mounded habit. One of the most highly rated cultivars in the RHS trial in southern England (Royal Horticultural Society 2018); floriferous and quite hardy for Tim Boebel in Zone 6 New York State (Boebel 2011, 2018). Selected 1994 by Ryoji Irie, Japan. Protected by US Plant Patent 18,508 and European Plant Breeders’ Rights (Google Patents 2024).

Hydrangea 'Rie05' (TOGETHER) is a neat, double flowered mophead (White House Farm, Kent, UK; 21 August 2015). Image Koen Camelbeke (Arboretum Wespelaar).

Hydrangea 'Rie05' (TOGETHER) in pink mode (White House Farm, Kent, UK; 21 August 2015). Image Koen Camelbeke (Arboretum Wespelaar).

'Rie09'

(You&Me® Series) Intermediate inflorescence form, initially resembling a lacecap, but with further sterile flowers scattered across the head, eventually enlarging to hide the fertile ones. Sterile flowers double, usually marketed as pink, but blueing is possible. Initially marketed as remontant, it flowers very poorly for Boebel (2011) in Zone 6. Selected 1994 by Ryoji Irie, Japan; protected by US Plant Patent 16,613 (Signature Hydrangeas 2024; Google Patents 2024).

Hydrangea 'Rie09' (ROMANCE) is usually marketed in pink. Image Maurice Foster.

Hydrangea 'Rie09' (ROMANCE) in lilac mode (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

Hydrangea 'Rie09' (ROMANCE) has double sterile flowers in inflorescences with intermediate mophead/lacecap form. Usually marketed as pink, blueing is absolutely possible (White House Farm, Kent, UK; 12 July 2023). Image Julian Sutton.

'Rosalba'

An important name in Europe for one of the “Beni” types of H. serrata, with white sterile flowers developing red-pink staining and ageing to crimson, not blueing. Leaves matt green and covered in bloom; height about 1.25 m. Japanese origin, the name apparently going back to Belgian botanist and nurseryman Louis Van Houtte, in 1865. There has been some confusion with other “Benis” (Bean 1981; Foster 2023; van Gelderen & van Gelderen 2004; Association Shamrock 2022). Using simple-sequence repeat markers, Reed & Rinehart (2007) found it identical at all but one locus with the plant they sampled as ‘Beni-gaku’, and concluded that they were probably identical; ‘intimately related’ might be a more cautious conclusion.

'Rosea'

Flowers with 3–4 entire sepals, light blue / pink, ageing greenish. Branches thin; height to about 2 m. One of the genetic founders of the European cultivars, a Japanese plant, probably a hybrid, brought to Britain in 1880 by Charles Maries working for the Veitch nursery; rarely grown today. (Foster 2023; van Gelderen & van Gelderen 2004)

One of the genetic founders of the European cultivars, Hydrangea 'Rosea' was brought to Britain from Japan in 1880 and given the often inappropriate cultivar name (stock received from Michael Haworth-Booth, at White House Farm, Kent, UK; 12 July 2023). Image Julian Sutton.

'Rosita'

Flowers blue / red-pink but tending strongly towards pink, small, in crowded heads; usefully early flowering, with some continuity. Height about 1.25 m; good in pots, which may account for its persistence in the trade. Introduced 1964 by Emile Draps, Belgium. (Foster 2023; van Gelderen & van Gelderen 2004; Promesse de Fleurs 2024; Association Shamrock 2022)

Hydrangea 'Rosita' flowers tend towards pink (Darley Park, Derby, UK; 28 August 2023). Image Julian Sutton.

'Rotdrossel'

(Teller Series, introduced 1987) Flowers tending towards red, brilliant deep red to purplish; sterile flowers large, sometimes in two rings. Vigorous, to 2 m (Church 2007; Foster 2023; van Gelderen & van Gelderen 2004). One of the hardiest Tellers (Edwards & Marshall 2019), flowering dependably in upstate New York (Boebel 2011). Rotdrossel is the Redwing, a migratory European thrush.

Hydrangea 'Rotdrossel' is one of the hardiest Teller cultivars (Darley Park, Derby, UK; 28 August 2023). Image Julian Sutton.

Hydrangea 'Rotdrossel': flowers range from brilliant red to purple according to aluminium availability (Darley Park, Derby, UK; 28 August 2023). Image Julian Sutton.

'Rotkehlchen'

(Teller Series, introduced 1979) Sterile flowers tending towards red, violet only on very acidic soils, with entire, heart shaped sepals; fertile flowers reddish. Compact; height about 1 m (van Gelderen & van Gelderen 2004; Promesse de Fleurs 2024). Richard Pitts, UK, reckons it makes the best shaped shrub of all the Tellers (pers. comm. 2023). Rotkehlchen is the European Robin.

Hydrangea 'Rotkehlchen' as a well formed mound (Avenue Cottage, Ashprington, Devon, UK; 17 October 2023). Image Julian Sutton.

Autumn tints in old flowers of Hydrangea 'Rotkehlchen' (East Ruston Old Vicarage, Norfolk, UK; 19 October 2024). Image Julian Sutton.

'Rotschwanz'

(Teller Series, introduced 1987) Sterile flowers tending towards red, often an intense wine-red, purple only on very acidic soils, sepals elongated and concave, giving a very distinctive star- or cross-like effect; fertile flowers pinkish; inflorescences large. Sturdy growth; height 1–1.5 m; foliage luxuriant and a little glossy, with good red autumn colour (Church 2007; Foster 2023; van Gelderen & van Gelderen 2004; Pan-Global Plants 2024). Rotschwanz is the Redstart, a European passerine bird.

Hydrangea 'Rotschwanz' making an impressive sight at White House Farm, Kent, UK (29 July 2023). Image Jack Aldridge.

Hydrangea 'Rotschwanz' tends strongly towards red. Image Maurice Foster.

On very acidic soils Hydrangea 'Rotschwanz' flowers may be purplish (private garden, Ayrshire, UK; 24 August 2023). Image Julian Sutton.

Royal Majestics® Series

A rather diverse group of both lacecaps ‘Hymmad II’ (MIDNIGHT DUCHESS), ‘Hymmad III’ (PRINCESS LACE), and mopheads ‘Blushing Bride’, ‘Hymmad I’ (QUEEN OF PEARLS) and ‘Mini Penny’, selected by Michael Dirr, University of Georgia. Initially licensed to McCorkle Nursery, Georgia.

Royalty® Collection

A European brand grown by De Jong Plant, The Netherlands; marketing appears focussed mainly on the pot plant trade, use in garden pots, tubs and baskets, etc (Royalty® Collection 2024). The range seems to have included all sorts of varieties from different breeders over the years. At the time of writing, ‘Horwack’ is listed (as ROYALTY® SCHLOSS WACKERBARTH), but in the past ‘Dancing Snow’/’Wedding Gown’, ‘Kompeito’, ‘Koria’, ‘Red Angel’, ‘Rie09’, ‘H211905’ and ‘Zorro’ have apparently all been there (Association Shamrock 2022).

The Royalty Collection is very widely sold in UK garden centres. Image John Grimshaw.