Ten million Easter Lilies, L. longiftonun, are sold every Easter Saturday in the United States – and have been sold on that day for many years past. Their production and supply has become an industry in its own right. Trade Associations and Government Research Stations issue detailed information, regular reports, and accurate timetables for every stage of production, so that the first blooms will open precisely on Easter Saturday. They advise on the prepreparation of bulbs, thedate, when forcing is to start and at what temperature the bulbs are to be stored. For instance, if the variety Croft is required to flower during early April, it must be planted at the beginning of the previous September, but prior to planting the bulbs are stored for five to six weeks at 50 DEG F (10 DEG C), or ideally at 39-45 deg F (4-7 deg C). Ace, another variety, requires eight weeks of the same treatment, while Estate is put into cold storage during October and November and planted in 6-inch at the beginning of December. Drainage requirements are met by putting a layer of coarse sand and broken crocks about inch deep in the bottom of the pot. The loam-based soil is mixed with peat in the proportion of 3:1 or 2:1, and the pH value of the mixture must be at least 6-5; carbonate of lime is added to correct excess acidity. Prior to forcing, the temperature is held at 50-57 deg F (10-14 deg C) and increased to 61 DEG F (16 deg C) during the forcing period. Every two weeks, applications of soluble nitrogenous fertilizers, mostly sodium or calcium nitrate (0-25 per cent) commence when the shoots reach a height of 2-3 inches, and are later followed by an application of a complete fertilizer.
In addition to the Easter Lily, us growers also force Asiatic varieties developed from L. tigrinum, L. x maculatum, L. x hollandicum, L. bulbifemm, L. davidii etc., particularly orange-red Enchantment, red Cinnabar, lemon-yellow Destiny, light-orange Harmony and the two gold-yellow types, Joan Evans and Croesus, as well as the Midcentury and Rainbow hybrids.
All these umbelliferous lilies have erect, saucer-shaped, grow 2 feet 6 inches-3 feet high and, depending on the exact variety, require forcing from 60 to 70 days. Varieties with outward-facing flowers usually their blooms to greater effect; among them are orange Valencia, light-yellow Prosperity, red Paprika and fire-red Fire King.
The reflexed flowers of the Fiesta hybrids are carried in loose panicles and are derived from L. tigrinum, L. davidii, and L. amabile. They grow taller than the last group and include the three well-known Citronella, Burgundy and Bronzino strains.
A longer forcing period, up to 20 weeks, is needed by the trumpet lilies, which again grow a little taller than the umbelliferous group. The varieties used are Royal Gold, Aurelian hybrids in their many forms and colours, Olympic hybrids, and the Centifolium hybrids, which include Green Dragon and Black Dragon.
Their bulbs are stored for a minimum period of four weeks before planting at temperatures from 33 to 35.5 deg F (0.55-2 deg C), unless the bulbs are imported and have already been prechilled. Plantings take place from January onwards and are timed for the first flowers to appear on 1 April. Bulbs are planted in pots or boxes at a density of 3-5 per square foot and covered with I-4 inches of good soil; water and fertilizer applications are increased as growth progresses. Forcing temperatures start at 50-5 5 DEG F (10-13 deg C) and are later increased to 59-64 deg F (15-18 deg C); bottom heat is to be avoided. Adequate ventilation is necessary during hours of sunshine, and increased light is required once the shoots appear, but too much hastens maturity. Bulbs which have been forced are not valueless, and can be usefully planted out in the open.
Forced lilies always find a ready market cither as pot plants or as cut flowers, and are in regular demand for special occasions like Mother’s Day. As bulb imports from the United States are somewhat expensive, increased multiplication facilities in Europe would be economically justified.
The professional florist or nurseryman selects his lily varieties for the forcing of pot plants or the production of cut flowers from a very different standpoint from that of the amateur gardener. The professional demands a variety with a short forcing time, with blooms which must be not too abundant and of only moderate size, with colour and shape of flower which must impress the customer and with robustness to withstand the journey fromto shop. Deep colours and the distinctive shape of the flowers make lilies able to compete with other plants.