Hybrid Lilies

Lilies have always been admired, although they have not always enjoyed the same soaring popularity as today. Once they were the rich man's plaything, when intrepid explorers and collectors sent back bulbs and seeds from Asia to Europe and America. These proved to be wonderful, new, exciting plants but often capricious, and many of the precious lilies lasted only a few years. The lily achieved its reputation for beauty and difficulty in these years between the end of the nineteenth century and the outbreak of the First World War.

The lily revolution really got underway in the 1950s, when the work of Jan de Graaff  began to make a huge impact on the gardening public. All the best forms of species and hybrids were brought together, and a large-scale programme of hybridization got under way. Phalanxes of new hybrids were introduced and proved to be so much more spectacular in growth and reliability as well as looks that they became irresistible. Globally, the main breeding work has been with the Asiatic hybrids, especially with those that have upward-facing flowers. Rapid propagation, quick and easy culture combined with attractive colors and flower forms that ensured easy packing and distribution, guaranteed success, making it the ideal cut flower. Many millions are sold annually in most European countries, in America, Australasia and all over the world, in florist's shops and all sorts of stores. Even those with only a modest interest in gardening have bought packets of bulbs or carried home pots of lilies in growth. The lily is proving the ideal plant for modern homes and gardens. This explosion of interest would not have taken place if the plants had remained as relatively idiosyncratic as the original species. Breeding programmes have cancelled out many of the inhibitions and problems with the wild plants and now we enjoy one of the easiest of plants.

Once you have tried a few Asiatic hybrids and found out how easily they grow in pots or in the garden, it is a short step to becoming an aficionado keen to try new kinds and types and also 'to spread the word'. The diversity allows you to specialize, perhaps rejoicing in the almost overwhelming Orientals, or finding the long-lived, naturalizing martagon types just the thing to bring magic to your garden.

Hybrid lilies are offered as cultivars and as mixed strains. Thus you can buy a cloned cultivar such as 'Enchantment', with all the bulbs producing identical plants, or bulbs of a strain such as Citronella which is a 'grex', a number of clones of the same or very similar parentage with many characteristics in common, but not producing identical flowers. Commercial growers and dealers are happy to increase both classes of products and to market them.

The wild lily increases mainly by seed, and this is a realistic way for gardeners to increase their stocks. Some cultivars have been in cultivation for well over fifty years and are still worth growing, but perhaps we should think of lilies as plants that go through a natural cycle, to be replaced after some years. Growers of species know that some kinds are naturally short-lived, and they always have replacement seedlings coming along. The hybrids are unlikely to die out in this manner, but we could help to keep all well by arranging a turnover. We can then keep our outstanding kinds and also constantly upgrade the collection or change its balance.

Division 1: Asiatic hybrids

The most widely grown type of hybrid lily in gardens worldwide is the Asiatic hybrids, bred largely from the earlier-flowering Asian species. So many species are involved in their ancestry that there is almost infinite variation among them, particularly in the flower colors, which may be brilliant or soft, in all the warm shades and white. There is also an extensive range of heights and flower forms.
Asiatic hybrids are derived from the following species and their varieties:

• L. amabile
• L. bulbiferum
• L. callosum
• L. cernuum
• L. concolor
• L. dauricum
• L. davidii
• L. lankongense
• L. leichtlinii
• L. pumilum
• L. lancifolium
• L. wilsonii

a: Upright-facing flowers.
b: Outward-facing flowers.
c: Pendent flowers.

Division 2: Martagon hybrids

As the name suggests these are derived from Lilium martagon and, initially, L. hansonii. Compared to the Asiatic lilies this is a very small group. Because they take longer from seed to flower - between five and seven years - results for hybridizers are slower and commercial interest has been slight.
Quite different in appearance from the Asiatic lilies, the whole plant is dainty, generally of medium to tall height bearing nodding, Turk's cap-shaped flowers that add a sense of Eastern mystery to any garden. Like the species' parents they flower early in the season, enjoy light shade and usually produce lots of flowers. They will also tolerate alkaline soil, thrive in heavy clay and loam but do well in sandy soils, too. Although they love shady places they can handle full sun. The flower color range is wide: white, yellow, orange, tangerine, mahogany, brown, lavender and lilac.
'Marhan', the first well-known hybrid in the group, was produced in 1891 in the Netherlands and is still available. It grows up to 6 ft. (1.8 m) with spotted flowers in a rich, orange-chestnut color.
A group of hybrids from Lilium martagon and L. hansonii, known as the Backhouse hybrids, was bred at the turn of the 20th century in England.
The Paisley hybrids appeared somewhat later and were a cross between Lilium martagon var. album and L. hansonii. In the second generation, the flower color range increased. From shades of gold and bronze they broadened to include clearer yellows and oranges as well as white and lilac.
These are normally healthy plants, resistant to virus and very cold hardy. Once planted, they will survive happily in one place for many years.
Martagon hybrids are derived from the following species and their varieties:

• L. hansonii
• L. martagon
• L. medeoloides
• L. tsingtauense

Division 3: Candidum hybrids

This is a small group and includes one of the oldest known hybrids, Lilium x testaceum, known as the Nankeen lily, a cross made in the early 19th century between L. candidum with trumpet-shaped flowers and L. chalcedonicum, with bright red Turk's cap shaped blooms. More recently L. monadelphum, L. cernuum, L. longiflorum and L. henryi have been used in crosses with L. candidum and various Asiatic hybrids using embryo rescue techniques. With stems growing to 4 ft. (1.2 m), the flowers are big and fragrant and appear in early summer.
'June Fragrance', bred in 1971 from the variety Lilium candidum salonikae with L. monadelphum, is a notable hybrid in its own right with creamy white, perfumed flowers in early spring. It has been used in subsequent years as a parent of more hybrids.
Candidum hybrids are derived from the following species and their varieties:

• L. candidum
• L. chalcedonicum
• L. monadelphum

Division 4: American hybrids

These are generally tall, stately plants bred from the western or Pacific Coast species of North America. The flowers are mainly Turk's cap-shaped, though less tightly reflexed than some of the species themselves. Like the martagon hybrids, they enjoy light shade, making attractive woodland plants with flowers in late spring or early summer. Best known are the Bellingham hybrids bred from Lilium humboldtii var. ocellatum, L. pardalinum and L. parryi.
In England Derek Fox used these to create his Bellmaid hybrids in 1968. Flowers are a rich yellow, darkening with age and are typically pendent, with reflexed petals. His Bullwood hybrids, introduced the previous year and bringing pink into the color spectrum, resulted in seedlings with peach-toned flowers and others where the typical orange-red of several species becomes a richer red.
American hybrids are derived from any North American species. Present-day hybrids in this division mostly originate from the western American species:

• L. bolanderi
• L. humboldtii
• L. kelloggii
• L. pardalinum
• L. parryi

Division 5: Longiflorum hybrids

L. longiflorum has had a long history of cultivation for the cut-flower and pot-plant trade. One form became associated with the name 'Easter lily' although now this is used with less precision for most forms of L. longiflorum. Over the years there have been, and still are, many named forms varying by fairly small taxonomic details but sometimes important commercial ones. Dwarf forms are useful for pots, ones with distinct foliage can be equally welcome. However, until fairly recently hybridization has not been an obvious part of the lily's activities. Now this has changed somewhat with a range of hybrids with the rather similar L. formosanum, hybrids which certainly grow with vigor and produce good crops of pure white trumpet flowers. These still are on the whole of more interest to commercial growers than the amateur gardener.
Longiflorum hybrids are derived L. longiflorum. Most such lilies in the trade are:

• L.longiflorum x Asiatic hybrids (Division 1)

a: Upright-facing flowers.
b: Outward-facing flowers.
c: Pendent or downward-facing flowers.

Division 6: Chinese trumpet and Aurelian hybrids

This group divides into two parts: the purebred trumpets, derived from the crossing of trumpet species and their hybrids, and the entire range of lilies that have in their breeding some of that tough species L. henryi - the antithesis of trumpet - form and a different kind of plant.
The pure trumpet hybrids have been derived from a number of species. These hybrids grown in gardens in temperate zones have been bred from L. regale, L. sargentiae, L. leucanthum, L. brownii and L. sulphureum. Some species, such as L. sulphureum and L. sargentiae, have never been plentiful in gardens as they are prone to succumb to virus.
A major advance in breeding took place when the de Graaff breeders raised large numbers of L. leucanthum centifolium and exercised a rigorous selection process to keep only those plants that appeared stronger and had wide-petalled flowers in a defined, pyramid shaped inflorescence. The inner white and the dark purple-mahogany of the buds were both intensified. The selected kinds were then mated with L. sargentiae, L. sulphureum and L. brownii. The selected progeny were originally marketed as Centifolium hybrids but then were renamed in 1955 and launched as the Olympic hybrids - a range of fine trumpets covering all colors from white, cream, lime and yellow to pink. Checking through the white-flowered ones led to further selection and reselection to end with the Black Magic strain with large white blooms with dark reverses. One outstanding plant was cloned and introduced as 'Black Dragon'.
The most successful of the yellow trumpets has been the Royal Gold series, sometimes marketed as 'the golden regale'. The progenitor of this was a yellow-flowered plant that turned up in the middle of a block of straight L. regale on the de Graaff farms. It was thought that L. sulphureum may have had something to do with the parentage and be the obvious reason for the flooding of the whole flower with yellow pigment. Certainly the original plant and the strain developed from it look very much of the L. regale stable.
From the progeny of both the cross L. regale x L. sargentiae and from batches of L. leucanthum centifolium appeared individuals with petals with pink margins and/or veining. These were gathered and interbred and suddenly pink flowers were raised which became the basis for the Pink Perfection strain. It is still not clear whether this breaking of the inhibition on the color zoning in the pinks was due to natural mutation, recombinations of genetic material or the accidental introduction of pollen from Aurelian hybrids which, with their L. henryi background, are free of zoning inhibitions.
It was the introduction of L. henryi material that enabled breeders to produce a much wider range of lilies that proved to be very hardy and amenable to a wide range of garden conditions.
The varying forms of these Aurelians necessitated their classification. The 'trumpet'-division was split into four  -these four classes have recently been modified so that they are separated by flower form.
Chinese trumpet and Aurelian hybrids are derived from the following Chinese species with purple bulbs:

• L.leucanthum
• L. regale
• L. sargentiae
• L. sulphureum
• L. henryi

a: Upright-facing flowers.
b: Outward-facing flowers.
c: Downward-facing flowers.

Division 7: Oriental hybrids.

The exotic beauty of the magnificent Oriental lilies is unsurpassed, not only among lilies but in the whole world of flowers. The typical Oriental hybrid is a late-flowering plant with broad alternate leaves. The flowers are usually large and showy, bowl-shaped, flat, or reflexed. Most have a powerful, sweet fragrance.
The preeminent characteristics sought in Oriental hybrids are identical to those required of other lilies: vigor, disease-resistance, and tolerance to virus-that is, the ability to grow well and show no serious symptoms even after being infected. These qualities must be present in lilies chosen as parents. Success is never achieved overnight; several generations were required to eliminate undesirable characteristics and produce today's superior forms.
'Empress of Japan', a huge-flowered, red-spotted gold band lily derived from crossing Lilium x parkmannii with 'Jillian Wallace', completed the Empress series. It lacked the virus tolerance of the other clones, however, and it rapidly succumbed to infection.
The Potomac hybrids were also prominent. Produced by Samuel L. Emsweller, they originated from the cross (Lilium auratum x L. speciosum var. punctatum) x L. speciosum.
Oriental hybrids are derived from the following species and their varieties:

• L. alexandrae
• L. auratum
• L. japonicum
• L. nobilissimum
• L. rubellum
• L. speciosum

a: Upright-facing flowers.
b: Outward-facing flowers.
c: Downward-facing flowers.

Division 8: Orienpet hybrids

This new group of hybrids between Orientals and Trumpets or Aurelians (and all the species that have contributed their genes to the common pool) combines the beauty and fragrance of the former with the adaptability and colors of the latter. In climates where summers are too warm for Orientals to thrive, the Orienpets take over, coming into bloom three to four weeks after the Asiatics. They are high performers in gardens from coast to coast across the United States; in Canada, growers in the cold prairie provinces are enthusiastic about their success, though they recommend mulching for winter protection.
Many of the flowers have deeply reflexed petals with Oriental lily colors while others have the color and character of the regale lilies but with outward, open petals. Most are large plants, often 6.5 - 8 ft. (2 - 2.5 m) tall with 20-60 flowers that are sensational for several weeks in the summer. So far the Orienpets as a group are not very fertile, though many crosses will form embryos without endosperm and this hybrid group is benefiting greatly from the use of embryo culture.
Some of the best of these hardy, beautiful lilies, are 'Scheherazade', 'Northern Carillon', 'Silk Road', 'Starburst Sensation', 'Northern Sensation' and 'Leslie Woodriff'.
Orienpet hybrids are derived from the crossing of species and hybrids from Division 6 and Division 7.
a: Upright-facing flowers.
b: Outward-facing flowers.
c: Downward-facing flowers.

Division 9: Species

All true species and their botanical varieties.

Division 10: Miscellaneous hybrids

All hybrids not covered in the above divisions.