Rhododendron Cultivars H

Halcyone (Lady Bessborough × souliei)

Flowers about seven in a lax truss. Corolla bowl-shaped, 31⁄2 in. wide, rosy pink in bud, opening white flushed with pink, heavily lined and speckled with darker pink. Leaves similar to those of R. souliei, from which it also derives the shape of its corolla. Medium growth. May. (Rothschild.) The description is from a commercial clone, which flowers well even where R. souliei never sets a flower-bud. In ‘Perdita’ (A.M. 1948) the corolla is less spotted and pinker (Rothschild Rhododendrons, pls. 51–2).

'Hamlet'

Orange tinged with pink, with a darker flare (M. Koster and Sons). A.M.T. May 23, 1936. Although classed as a Mollis it flowers later than most members of that group.

'Hammondii'

A hybrid with, probably, the same parentage as ‘Arbutifolium’ is ‘Hammondii’, distinguished by its narrower leaves, up to 13⁄4 in. long and 1⁄2 in. wide.

'Handsworth Early White'

Flowers about ten in the truss on erect pedicels. Corolla funnel-shaped, 2 in. wide, pink in the bud, opening white, almost unmarked. Leaves narrowly oblong-elliptic to oblanceolate, 5–7 in. long. Compact and low-growing. March or April. (Fisher, Son and Sibray.) A hybrid of R. caucasicum.

'Hardijzer Beauty'

Similarly coloured flowers to ‘Ria Hardijzer’ but more robust, with leaves up to 2 in. long, and with more flowers in the total cluster – up to sixty (A.M.T. May 12, 1970)

Harrisii (arboreum × thomsonii)

This cross was first made about 1880 in Lord Swansea’s garden at Singleton near Swansea by his head gardener Harris, who later set up his own nursery. The original plants were up to 25 ft high when Millais saw them in 1915. The cross was later made at Caerhays with better results and the plants from this cross are usually treated as a separate grex under the name Red Admiral. It was also made at Penjerrick, where it was named Tregedna. These hybrids are as early flowering as R. arboreum, and not common outside the milder parts. The flowers are fewer in the truss than in R. arboreum, with a more pronounced calyx, and vary in colour from crimson to blood-red. The leaves are usually (to the naked eye) glabrous beneath, relatively broader than in R. arboreum and usually obtuse at the apex.

'Harvest Moon'

Clear primrose-yellow with a slightly darker flare (Knap Hill; Slocock). A.M.T. May 26, 1953. A lovely azalea but not a strong grower. It associates well with the rhododendron ‘Purple Splendour’.

'Hatsugiri'

Corolla about 1 in. wide, magenta-purple. Calyx normal. Leaves dark green, oblanceolate. Low, dense habit, 2 to 3 ft high, much more in width. Late April or early May. A Kurume azalea closely related to ‘Amoenum’ but with a normal calyx, differing from most Kurumes in its dull darkish green leaves. Very hardy and free-flowering. F.C.C.T. May 12, 1969.

Rhododendron 'Hatsugiri' on the rock garden at the Royal Botanic Garden Edinburgh, UK. 19 April 2025. Image Tom Christian.

Hawk ('Lady Bessborough' × wardii)

This well-known Exbury hybrid unites two yellow-flowered members of the Thomsonii series – R. campylocarpum and R. wardii – with the tall-growing, late-flowering R. discolor of the Fortunei subseries. Lionel de Rothschild made the cross twice. The first batch, which started to flower about 1940, had R. wardii KW 4170 as its parent, and its best known clone is ‘Jervis Bay’. This has about 10 flowers to the truss. The corolla is widely funnel-shaped, 3 in. across, primrose-yellow with a deep red eye. It received an A.M. in 1951. ‘Crest’, which received an F.C.C. in 1953, is from the repetition of the cross. The flowers are about twelve in the truss. The corolla is very widely funnel-campanulate, 4 in. across and 11⁄2 in. deep, with seven rounded lobes, a lovely clear primrose-yellow shading to deeper below the upper lobes, unmarked except for faint streaking at the very base of the throat (Rothschild Rhododendrons, pl. 23).

‘Crest’ is so different in its flowers from those of the first batch that it has been suggested that some other form of R. wardii was used as the parent. Or it may be that mere chance decreed that the combination of characters seen in ‘Crest’ appeared in the second and not in the first batch. The seven lobes come from R. discolor, but KW 4170 (‘Lemon Bell’ as Kingdon Ward called it), with its unblotched corolla, has asserted itself over the other two parents – R. campylocarpum “var. elatum”, with its red eye, and R. discolor, which usually imparts a streaked throat to its offspring. ‘Crest’ is generally acknowledged to be the finest yellow-flowered hybrid yet raised, but may in time be supplanted by its offspring, of which a number have already received awards. See the note by T. H. Findlay in R.C.Y.B. 1967, pp. 73–4.

The clonal name ‘Hawk’ is linked in the International Register to the form that received an Award of Merit when shown from Windsor by the Crown Estate Commissioners in 1949. Whether the plants in commerce as ‘Hawk’ are of this clone it is impossible to say. The foliage in the Hawk grex is mostly oblong-elliptic and obtuse, truncate or slightly cordate at the base, up to about 7 in. long. The plants flower in late April or May and attain a height that varies somewhat with the clone.

Using ‘Crest’ as one parent, T. H. Findlay has raised a number of fine hybrids for the Crown Estate Commissioners, Windsor, which are not yet generally available (1975). The following have received awards and been described in the Rhododendron and Camellia Year Book (the second parent is given in brackets): ‘Arborfield’ ([x] ‘Loderi Julie’), A.M. April 30, 1963, R.C.Y.B. 1964, p. 134 and fig. 54; ‘Binfield’ ([x] ‘China A’), A.M. May 5, 1964, R.C.Y.B. 1965, p. 166 and fig. 41; ‘Queen Elizabeth II’ (× Idealist), A.M. May 2, 1967, R.C.Y.B. 1968, p. 133 and fig. 6, see also R.C.Y.B. 1969, p. 109; ‘Theale’ (× Penjerrick), A.M. May 3, 1966, R.C.Y.B. 1967, p. 166 and plate 6; ‘Warfield’ (× Jalisco), A.M. May 18, 1970, R.C.Y.B. 1971, p. 185 and fig. 66.

Another hybrid from ‘Crest’ is ‘Cara Mia’, raised by Edmund de Rothschild at Exbury from a cross with ‘Aurora’; A.M. May 3, 1966, R.C.Y.B. 1967, p. 163 and fig. 37.

'Helene Schiffner'

Flowers 12 to 14 in a compact hemispherical truss 3 to 4 in. wide. Calyx almost nil. Corolla funnel-shaped, about 2 in. wide, mauve in the bud, becoming a singularly pure and hard white, unmarked or with very faint brown markings. Leaves dark green, glossy, lanceolate to oblanceolate, up to 5 in. long, about 13⁄4 in. wide. Dwarf spreading habit to not much more than 5 ft. Late May. F.C.C. 1893, when shown by the nurseryman Seidel of Stiesen near Dresden. A remarkable rhododendron, easily recognised by the glaring whiteness of its flowers and its comparatively dwarf habit. It seems to have the ‘blood’ of both R. ponticum and R. caucasicum in it. The name is usually incorrectly given as “Hélène Schiffner”.

'Hexe'

Mention may be made here of another of Forster’s hybrids, the once very common ‘Hexe’, which is the result of a cross between ‘Amoenum’ and the Indian azalea ‘Due de Nassau’, raised in 1878. Being of dwarf habit and easily raised from cuttings, it was a very popular pot plant early this century, and was also used as a stock for grafting the Indian azaleas. The flowers are hose-in-hose, rosy crimson, 13⁄4 in. wide. A.M. 1907. The name ‘Hexe’ has been wrongly used for a quite different azalea, which is vigorous, late-flowering, and has semi-double flowers with a normal calyx.

'Hinodegiri'

Corolla 1 in. or slightly more wide, with a slender tube, bright red (53b), deepening in the throat. Calyx normal. Leaves light glossy green, the upper (persistent) ones obovate, up to 5⁄8 in. long. Late April or early May. Fairly compact habit, eventually 4 or 5 ft high (Kurume; Wilson No. 42). A.M.T. 1965. One of the best known of the Kurumes, not quite hardy. It had been introduced before Wilson sent it.

'Hinomayo'

Flowers solitary or in pairs. Corolla 11⁄4 in. wide, Phlox Pink, slightly speckled in the throat. Calyx normal. Leaves light glossy green, the upper ones mostly oblanceolate-spatulate. Dense habit, eventually 5 ft high (Kurume). A.M. 1921; Award of Garden Merit 1954. The most popular of the Kurume azaleas and one of the hardiest, already established in gardens before the introduction of the ‘Wilson Fifty’. The flowers are of such a clean shade of pink, and produced in such abundance that the effect of a large group growing in full sun is rather overpowering. It is prettier as an individual specimen or small colony, and flowers quite well in dappled shade. It is one of the most deciduous of the Kurumes, regularly shedding most of its summer leaves, at least in colder gardens, but perfectly bud-hardy. For an interesting note on this azalea by K. Wada, see R.C.Y.B. 1970, pp. 181-3, where it is pointed out that the correct Japanese name is ‘Hinamoyo’.

'Hollandia'

Flowers about 14 in the truss. Corolla slightly frilled, about 3 in. wide, carmine pink, shading to paler at the centre of the lobes, with brown speckling on the centre lobe. Leaves elliptic to oblanceolate, dark sea-green. May. (‘Charles Dickens’ × ‘Pink Pearl’; L. J. Endtz and Co.) This is not the same as the hybrid which received an A.M. in 1925. The latter was raised by M. Koster and Sons, and had bluish-mauve flowers with a mustard-coloured flare.

'Homebush'

Double, about sixteen in dense, rounded trusses, deep carmine-pink, about 11⁄2 in. wide. Raised at the Knap Hill Nursery before 1925 and distributed by Messrs Slocock. A charming azalea, similar to the Rustica Flore-pleno group. A.M.T. May 31, 1950. Numerous doubles, mostly with fragrant flowers, have been raised recently at Knap Hill by Donald Waterer, and were named in 1974.

Rhododendron 'Homebush'. Corsock, Dumfriesshire, UK. 28 May 2025. Image Tom Christian.

'Hortulanus H. Witte'

Bright orange-yellow (Mollis; M. Koster and Sons).

'Hotspur'

Flame-red with a yellow flare, about 4 in. wide (Knap Hill-Exbury; ‘George Reynolds’ × Waterer’s orange seedling). A.M. May 29, 1934. Other seedlings were raised from this cross, similar in size and shape of flower, but of different colouring. Two of these, ‘Hotspur Orange’ and ‘Hotspur Red’, are sometimes sold as ‘Hotspur’ simply. Rothschild Rhododendrons, pp. 33–4, 105, plate 48.

'Hugh Koster'

‘Hugh Koster’ somewhat resembles ‘Doncaster’ in flower and foliage, and is a hybrid of it, but the corollas are rather lighter in colour, and the style and stamen-filaments are white, not pink as in ‘Doncaster’. It is also taller, but still of bushy habit. (Koster and Sons. A.M.T. 1933.)

'Hugh Wormald'

Flowers about 18 in a large, pyramidal truss. Corolla funnel-shaped, 23⁄4 in. wide, bright cerise pink with a dark brown flare on the upper lobe, the other lobes with a white stripe down the centre. (Koster.) Admired by Millais but now uncommon (Millais, Rhododendrons, 2nd series, pl. fac. p. 58).

Humming Bird (haematodes × williamsianum)

Inflorescence with four or five flowers. Calyx large, spreading, coloured like the corolla, which is open campanulate, 21⁄4 in. wide, carmine-pink, fleshy, unspotted. Leaves elliptic or roundish elliptic, rigid, about 11⁄2 in. long, rich green above, paler and thinly coated beneath; petioles brownish red, bristly-glandular. Compact habit. April or early May. (J. C. Williams.) A pretty rhododendron in flower, with good foliage. ‘Elizabeth Lockhart’ is a sport from this raised by Prof. R. D. Lockhart of Aberdeen, in which the young foliage is dark chocolate brown, and even the mature stems, leaf-blades and petioles are deeper than normal. The flowers too are darker than normal, near to Indian Lake.

'Hyperion'