Detailed Guide to Cut Lily Production Techniques
Lily roots prefer a substrate with good drainage, aeration and water retention. Heavy clay substrates are unsuitable for growing lilies, as such substrates easily become compacted and hardened. Increasing the organic matter content of the substrate can noticeably improve its drainage, aeration and water retention. Lilies like to grow in a substrate with a moderate organic matter content. Adding fermented, fully decomposed cow manure or rice hulls to the growing substrate is ideal; the cow manure or rice hulls mixed in must have been decomposed for more than one year. Undecomposed material or manure from other animals such as chickens, horses and pigs should be avoided as far as possible, because these materials provide too much nutrition and too high fertility for lilies, and after application they may cause the substrate EC value to rise sharply, very likely burning lily roots. Fermented, fully decomposed rice hulls or cow manure contain a small amount of nutrients and mainly serve to improve the physical properties of the substrate. Applying untreated peat moss can also achieve a similar effect, and using peat or grass peat can also lower the EC value of the substrate, an effect that rice hulls or cow manure cannot achieve.
In lily production, do not use growing substrates containing chlorine or fluorine. When amending substrates, many people use perlite or vermiculite to improve water retention, aeration and drainage. Perlite or vermiculite can give good results, but some perlite or vermiculite of unknown origin contains chlorides and fluorides, which are very harmful to lilies. Excessive fluoride in particular causes very obvious leaf scorch in lilies (similar to leaf scorch disease, except the affected parts may be the lower leaves or the whole plant).
II. Bulb Treatment
After receiving the bulbs, place the still-frozen bulbs in a dark environment kept at 10°C-15°C to thaw slowly for 12-48 hours. When thawing, open the plastic covering. Do not thaw them in a high-temperature environment under direct sunlight. After thawing, they should be planted immediately. If they cannot be planted, they can be stored for 2 weeks in a dark environment at 0°C-2°C with no strong wind passing through. High-temperature storage and excessively long storage can cause lily bulbs to sprout prematurely and develop roots prematurely, which affects the later quality of the lilies. Even if the price is cheap, growers had better not buy lily bulbs that have passed their optimal storage period, because the flower and stem length of such lily bulbs cannot be guaranteed.
Before planting, lily bulbs should be disinfected with fungicide. In China, the soaking method is generally used, while many growers abroad use the spraying method to avoid secondary contamination and cross-infection of lily bulbs by pathogens during soaking.
III. Cultivation and Planting
To avoid damaging lily bulbs, thawed bulbs should be planted immediately and should not be stored too long. There are three main methods of lily production cultivation: field planting, box planting and raised-bed planting. Generally, Asiatic hybrid lilies and Longiflorum hybrid lilies are mostly grown by field planting; this cultivation method requires low initial investment and suits extensive management. Oriental hybrid lilies, however, are mostly grown by box planting or raised-bed planting; this method has high requirements for facilities and higher investment, and its management operations are relatively complex, but it can control more environmental factors and suits intensive management.
1. Producing cut lilies by field planting.
(1) Early-stage management after planting (the first three to four weeks after bulb planting). For winter lily production, raised beds can be used. In winter, the soil substrate temperature is low; using raised beds allows the bed surface to receive more light and reduces the effect of low temperatures conducted from deep underground on the soil substrate temperature. Generally, raised beds can noticeably increase the ground temperature by 2°C-3°C. For summer lily production, the adverse effects of high temperature on lily growth should be avoided as much as possible, so low beds can be used. When using low beds for lilies, pay attention to the drainage of the soil substrate. Never use low beds in low-lying and open-air production areas, to avoid backflow of rainwater and flooding. When raised beds are used for lilies or other crops, more salt is more likely to accumulate on the surface of the substrate soil of the raised bed, and a higher EC value has a very obvious effect on lily stem length, so if the EC value of your irrigation water is on the high side (between 1 mS/cm and 1.5 mS/cm), try not to use raised beds.
Whether raised beds or low beds are used, the bed width generally does not exceed 1.2 m. This is mainly to make planting and harvesting and other operational management during production and planting convenient. A bed height of about 20 cm is sufficient. The bed length can be determined according to the greenhouse specifications. When building the beds, never make the soil substrate too compact, and do not pat or press it too much, so as not to worsen the substrate's aeration.
Before planting, reserve positions on the bed surface for drip irrigation facilities and support poles. In cut lily production, support nets with a mesh side length or diameter of 12-16 cm are more commonly used. Set up a support pole about every 3 m, and choose sturdy, corrosion-resistant support poles such as thin iron pipes that will not be eaten by pests. Bamboo poles and wooden poles can also be used, except that such organic support poles are prone to rotting from water intrusion and being bored by pests. Once such support poles break, the entire patch of lily stems will also break and fall over, and all previous efforts will be wasted.
When planting the bulbs, carefully take out the lily bulbs, use a small trowel or bulb planting trowel to dig small holes on the bed surface larger than the bulbs, and place the lily bulbs vertically with the apical bud facing up, perpendicular to the base surface. If the lily bulbs are placed crookedly, their stem buds will grow at an angle; after the stem buds grow out of the substrate surface, they will readjust their growth angle themselves and return to growing perpendicular to the substrate surface. When placing the bulbs, do not press too hard, to avoid damage from improper force or breaking the basal roots of the bulbs. After placing them, cover them immediately with the soil substrate. For summer production, dig holes 8-10 cm deep; for winter production, dig holes 6-8 cm deep. During planting, dig one and cover one; do not leave lily bulbs exposed to the greenhouse environment for too long, because prolonged exposure will cause the bulbs to lose water and the roots to dry up, which will seriously affect the growth and development of lilies in the early stage. When covering with the soil substrate, also be careful not to let the properly positioned bulbs tilt again, otherwise after the bulbs sprout there will be the problem of uneven distribution of stems on the bed surface.
The planting density of lily bulbs should be comprehensively considered according to variety characteristics, bulb size, light intensity, soil substrate density, production season and so on. For example, in seasons with sufficient light, the production density can be denser; in seasons with poor light, the planting density should be sparser.