A new generation of crosses has produced the most dramatic blooms yet
by CAROL HALL
LILIES BREAK THE RULES. Most gardeners, asked to compare the virtues of hybrid and species forms of the same genus, would give hybrids the nod for looks, flower form, size, substance, color range, and short-term vigor, while species get credit for hardiness, disease and insect resistance, weather tolerance, adaptability, and longevity. Not the genus Lilium, the true lilies. While their mesmerizing beauty and fragrance has kept some species lilies in cultivation for 3,500 years, growing them outside their native habitats has always been dicey. Some species need lime; others can’t stand a trace of it. Some require damp, shady woodland; others turn up their toes in anything less than full sun and perfect drainage. Some are hardy but notoriously difficult to establish; some are easy to establish but abruptly short-lived; some are long-lived but uninspiring or unscented. Still others have huge, exquisite flowers with intoxicating scent but are sickeningly prone to botrytis and a host of other fungal diseases. Many (if not most) species lilies are vulnerable to incurable and highly contagious viruses.
Until 50 years ago, however, these frail beauties were virtually the only true lilies available. What this meant was that with the exception of locally adapted species and a few hardy stalwarts, such as tiger lilies (L. lancifolium) and showy lilies (L. speciosum), success with the genus was the horticultural equivalent of a perfect triple axel on ice skates. Who could blame lily lovers for wanting the distinctive grace, beauty, and perfume of species forms, but with greatly increased health, vigor, garden persistence, hardiness, and adaptability—to say nothing of a much wider range of color and flower form?
HYBRIDIZERS TO THE RESCUE
Unfortunately, hybridizing lilies for these qualities simultaneously has never been simple, and it wasn’t until the 1920s and ‘30s that a Dutch immigrant named Jan de Graaff, working in Oregon, made real progress. Still, healthy hybrids were not feasible on a commercial scale until the 1950s. At that point, the lily world was carved into eight somewhat esoteric, firmly separated divisions based on hybrid parentage, plus a ninth comprising all botanical species.
Of these nine divisions, three quickly came to the fore: the colorful, hardy, easy-care but scentless Asiatic hybrids (Division 1); the tall, powerfully fragrant but color-limited trumpet hybrids (Division 6); and the spectacular, exotically perfumed but slightly fussy and unpredictable Oriental hybrids (Division 7). All three proved far healthier, easier to grow, and longer-lived than most of their species forebears, leaving little, if any, room for improvement. Or so it seemed until the 1970s, when a new breeding technique made it possible to cross lilies from different divisions with each other, an achievement previously considered biologically impossible.
In part, the new technique was nothing new. Certain interdivisional crosses were previously possible up to a point, because their parental DNAs were compatible; but the newly fertilized seeds failed to survive because their food supply did not develop. They simply starved.
But in the early 1970s, breeders discovered that these embryos could be removed from the pod at the first sign of collapse and placed in a sterilized growing medium, whereupon they would continue to grow and develop normally. Embryo rescue, as the technique is called, is just that: no artificial gene manipulation is involved, and the resulting plants are emphatically not genetically modified organisms.
The results of embryo rescue have been nothing short of fantastic. Lily breeders from around the world—the Netherlands, Canada, New Zealand, and the United States (particularly in the Pacific Northwest) have created interdivisional hybrids with unsurpassed vigor, greatly increased tolerance of both heat and cold, a surprising degree of drought tolerance, and exceptional resistance to viruses and other diseases. The new cultivars also have longer blooming times and greater garden persistence. Most are highly fragrant; all are outstandingly beautiful.
TRUMPETING THE NEW HYBRIDS
Trumpet lilies figure prominently in the complex ancestry of interdivisional hybrids, giving rise to a cacophony of names. The terms Orienpet and OT for Oriental/Trumpet crosses, and Asiapet and AT for Asiatic/Trumpet crosses are now standard—although Asiatic/Trumpet crosses may be known by some as AA, for Asiatic/Aurelian (a type of trumpet). Other designations derive from crosses between Division 5 (hybrids of the trumpet-shaped Easter lily) with specimens from other divisions. These include longipet (Lilium longiflorum/Trumpet), LO (L. longiflorum/Oriental), and the slightly better-known LA hybrids (L. longiflorum/Asiatic).
Most prominent among interdivisional hybrids are the tall, very vigorous, heat-tolerant, and widely adaptable Orienpets. Characterized by huge, fragrant, outward-facing flowers, these begin blooming mid-July to early September, depending on climate, and can continue for weeks. Most grow four to six feet tall and are hardy in USDA Zones 3 (where mulch is advisable) to 9. Among some of the most beautiful are ‘Anastasia’, ‘Catherine the Great’, and ‘Silk Road’.
Asiatic/Trumpet crosses grow on sturdy, vigorous plants three to five feet high, start blooming in late June to July, and are fully hardy in Zones 3 to 9. Fragrant, long-stemmed flowers are large, wide petaled, and heavily textured; colors are mostly in the ivory-gold to peach-orange range. Flower shape may be reflexed and slightly pendant, as in the pastel, darker-centered Seabreezes strain, or more bell-shaped and outfacing, as in the Canadian Belles series. The latter, developed in Manitoba, Canada, by Lynn Collicut and Wilbert Ronald, who kept cold hardiness in mind, are hardy to Zone 2 (that’s -50°F) with mulch.
Sometimes called Easter lily hybrids, these L. longiflorum/Asiatic crosses grow three to four feet tall, bloom in June and July, and are hardy in Zones 3 (with snow cover or heavy mulch) to 9. Wide-petaled, lightly fragrant flowers occur mainly in pastel tones and best hold their color in light shade. Individual plants are not long-lived in the garden—they were first developed in the Netherlands by noted breeder Peter Schenk for the cut-flower trade—but bulbs multiply quickly and prolifically for continued garden presence. Examples include ‘Aladdin’s Dazzle’, ‘Desert Song’, and ‘Hello Dolly’.
The Bulb That Never Sleeps
True lilies are never completely dormant, even when no top growth is visible, so always plant lily bulbs as soon as you get them, whether in fall or spring. (Potted lilies may be planted at any time—with care—even when they are in full bloom.) Fallplanted bulbs give the best performance the first summer, but early spring planting is also fine, and advisable where winters come early or are severe. Regardless of season, water freshly planted bulbs well and mark the site to prevent accidental damage to bulbs or emerging shoots.
State-of-the-art cold storage now keeps fall-harvested bulbs in prime condition for spring planting, but packaged bulbs on display racks may start into growth while still inside their plastic bags. If immediate planting is not possible, bulbs can be refrigerated for a few days in the vegetable crisper. (Open the bag to prevent excess condensation.) If bulbs are dry, plump them up in moist peat moss until planting.
The need for year-round moisture as well as excellent drainage also governs planting depth. Some sources recommend covering larger bulbs with as much as eight inches of soil in cold-winter areas. However, since most soil nutrients (and best drainage) lie in the top three to five inches of soil, it’s better to err on the shallow side, especially in heavier soils, and cover with deeper mulch instead. In lighter soils, contractile roots will pull bulbs to a lower depth if necessary. If you have any doubts about the drainage, plant on a slope or in a raised bed. A three-inch layer of organic mulch, advisable in all areas, will help even moisture fluctuations and reduce the need for summer watering. Natural bulk fertilizers—such as compost or leaf mold—do double duty as mulch, giving best long-term feeding results by most closely approximating ideal nutrient levels as well as the ideal moisture-drainage balance.
Lilies excel as container subjects. Plant bulbs deep, at two-thirds the depth of the container, to encourage self-support of stems, and place the pot where it will remain cool but the flowers will get at least a half a day of sun. Keep soil consistently moist, cut back on watering when stems yellow, then bring the pot into a sheltered area and keep soil barely moist over the winter. When new growth resumes, top-dress with fresh potting soil and gradually increase water and exposure.—C.H.
Not a specific cross, but the name of a hybridizing company established by geneticist Judith Freeman, a pioneer and leading authority in embryo rescue culture who now owns her own nursery, The Lily Garden, in Vancouver, Washington. Columbia-Platte introductions include many now-famous Orienpets (’Anastasia’ and ‘Scheherazade’ among them), as well as newer Orienpets—for example, ‘Pizzazz’. Other introductions by Freeman include Asiapets, such as ‘China Express’; trumpet crosses, such as ‘Sinfonia’; Asiatic crosses, such as ‘Yellow Whoppers’; and species crosses, such as ‘Viva’.
Freeman was also instrumental in developing the now-classic smallflowered, pendant, reflexed Turk’s-cap hybrids, including ‘Tinkerbell’, ‘Peach Butterflies’,’White Butterflies’, ‘Coral Butterflies’, and ‘Tiger Babies’. She also introduced many of the now-familiar brushmark Asiatic lilies, which sport short, vivid dark streaks in their flowers’ centers—for instance, ‘Brushstroke’ and ‘Cathedral Windows’.
Without a doubt, there are more wonders to come. Modern hybridizing has already produced true genetic dwarf lilies ideally suited for container culture. Look for the Pixie series of Asiatic species crosses; they grow only 8 to 14 inches tall and boast high bud counts, handsome foliage, and relatively large flowers in innumerable clear, bright colors. Meanwhile, true dwarf Orientals have all the perfume and substance of Orientals, on plants only 10 to 16 inches tall. Both types are hardy, easy to grow, and highly resistant to disease.
From all indications, lily hybridization is a continuing passion. Still on the wish list are true white and true pink Orienpets, peach and true red trumpets, and Asiapets in an expanded color range. But whatever new, fascinating, and eagerly anticipated colors and forms are still yet to be, they have nothing on the interdivisional hybrids that already exist. Lilies just can’t get any better than this. H
For sources of plants featured in this article, turn to page 72.