A detailed guide to soilless lily cultivation, teaching you how to grow lilies well
Lily propagation methods
To produce high-quality lily cut flowers, the first requirement is healthy, disease-free bulbs. Lily propagation (also called “bulb production”) can generally be divided into post-flowering bulb nurturing, bulbil propagation, scale cutting, bulbils propagation, sowing, and tissue culture, etc. Now here is an introduction to several main propagation methods.
(1) Post-flowering bulb nurturing, also called large bulb propagation. When the lily begins to bloom, the new underground bulb has already formed, but has not yet grown into a mature “large bulb.” Therefore, when harvesting cut flowers, while ensuring the stem length, leave as many leaves as possible to favor the nurturing of the new bulb. 6-8 weeks after flowering, the new bulb matures and can be harvested. Whether subsequent forcing cultivation succeeds depends entirely on the degree of maturity of the new bulb.
(2) Bulbil propagation. At several nodes below the ground on the lily stalk, a number of small bulbs will form. These small bulbs have a sound root system and can be planted separately to be grown into commercial cut flower bulbs. At first, the small bulbs can be planted in plastic boxes and cultivated in a mixed substrate made of peat, vermiculite, and fine sand in a 2:2:1 ratio. One year later, plant the grown small bulbs in cultivation beds or furrows. Growing small bulbs requires more fertilizer; the principle of fertilizing is little and frequent, and the nutrients should be complete. Mixing long-acting organic fertilizer into the cultivation substrate is a more ideal fertilizing method. During the second year of bulb cultivation (commonly called bulb growing), some will produce flower buds; these flower buds should be removed promptly to favor the cultivation of the underground bulb. After 2 years of cultivation, the small bulbs can be used as flowering bulbs. After harvest, they should be graded by specification, and diseased bulbs removed and boxed.
(3) Bulb scale cutting. Using healthy scales for cutting is one of the methods for propagating lily bulbs. For the cutting substrate, choose peat:fine sand = 4:1, or use pure peat. Insert 1/3 of the scale (or 3 cm) into the prepared substrate. After insertion, keep the substrate moist, avoid waterlogging and high temperatures, and prevent the scales from rotting. Maintain the temperature at 22-25°C, and keep the relative air humidity at about 90%. There are no special requirements for sunlight, but long-day conditions are more favorable for the formation, growth, and development of small bulbs. After 2 weeks, visible small bulb-like protrusions appear at the base of the scale; after 3 weeks, 1 or several fleshy roots gradually grow from the base of the small bulb; after 1 month, small leaves can emerge, and it becomes a small bulb capable of living independently.
(4) Tissue culture propagation. Lily tissue culture is relatively easy to establish. Explants that can be used for tissue culture include scales, leaves, bulbils, floral organs, young stem segments, root segments, etc., with scales being the most convenient. Peel off the middle part of the scales from healthy, disease-free bulbs, disinfect them, and inoculate them onto a prepared medium. For different species or cultivars of lilies, the hormone content and types are all different. For example, first use MS medium + BA 0.3 mg/L + NAA 0.1 mg/L to make the material differentiate shoots. Then transfer to rooting medium MS + NAA 0.8-1.0 mg/L + BA 0.2 mg/L to continue culturing, and a large number of daughter bulbs can be produced. Lily culture conditions: temperature 22°C-26°C, light 1000--1200 lux, 10-14 hours of illumination per day, medium pH 5.6-5.8.
Lily scale cutting propagation
1 New bulb roots 2 New bulb 3 New bulb aboveground leaves
Small bulbs propagated by the above methods still need 1-2 years of cultivation to reach bulbs for forcing cultivation.
Cultivation management
Taking the cultivation of cut flowers for March-May, the tightest supply period in the cut flower market, as an example, soilless lily cultivation usually adopts the substrate trough planting method, and the organic ecological soilless cultivation method is especially suitable. For the cultivation substrate, choose peat, leaf mold, sawdust, mushroom residue, vermiculite, perlite, bone meal, plant ash, etc., plus organic solid fertilizer to make an ideal composite substrate. The pH value should preferably be 5.5-6.5.
For lilies that need to bloom from March to May, the bulbs that have undergone low-temperature treatment can be taken out successively from early December of last year to late February and planted in batches. As long as management is proper, they can bloom on schedule.
Planting density varies depending on factors such as cultivar, bulb size, and light. For bulbs of grade one or above, no less than 40 cm × 30 cm; for grade two bulbs, no less than 30 cm × 20 cm. The planting depth is generally 3 times the bulb diameter; too shallow easily causes the plants to lodge. After planting, if the substrate is relatively moist, there is no need to water immediately; watering again 6-10 days after planting is more favorable for early new root growth.
After planting, maintaining a suitable temperature in the greenhouse is one of the important conditions for good lily growth and flowering. For the first 15-20 days, the soil temperature should preferably be kept at 15-18°C; this temperature range is most suitable for root growth and leaf development. If the temperature exceeds 22°C, it easily delays flowering or reduces flower quality.
3-4 weeks after planting, from sprouting until the plant reaches a height of 10-15 cm, this stage is the vegetative growth period. During this period, strengthen light and fertilizer-water management, watering with nutrient solution 1-2 times per week or spraying foliar fertilizer once, to promote leaf differentiation and growth.
When more than 10 nodes of visible leaves are present, the flower bud differentiation process has already begun, and the plant shifts from vegetative growth to the reproductive growth stage. This stage is crucial for cut flower production. In cut flower pricing, the more flowers per stem, the higher its economic value. Factors affecting the number of flowers per cut flower stem, besides bulb size, are also directly and closely related to the cold treatment method and duration, cultivar, greenhouse forcing temperature, rooting speed and number of roots, light intensity, and fertilizer-water management during forcing cultivation. In cultivation management techniques, applying root-outside topdressing when most plants are in the undifferentiated flower bud state can noticeably increase the number of flowers per stem. The method is to carry out foliar fertilization on 2 consecutive days respectively: the first time with 0.1% potassium nitrate, the second time with a mixed solution of 0.05% ammonium sulfate plus 0.1% potassium nitrate.
From the visible small flower buds in the apical leaf cluster to the opening of the first flower bud is the fourth stage. This stage is mainly controlled by temperature; under normal cultivation management conditions, the time is 30-35 days.
In cut flower production, besides staged planting, the leaf unfolding speed can also be used to regulate the growth and flowering period, that is, on the basis of basic leaf formation, use temperature to control leaf elongation speed and achieve the purpose of properly regulating the flowering period.
Cut flower lilies should be harvested after 2-3 flower buds have colored. Harvesting too early will cause the flower buds to open poorly, and some flower buds may even fail to open. But harvesting too late, when the flowers have already opened, pollen is easily shed and contaminates the petals, which lowers the quality of the flower stem; opened petals are easily damaged during harvest and packaging, which also greatly reduces the selling price of the flower stem. After harvest, sort the flower stems, group them by the number of flowers per stem, make 1 bunch of every 10 stems, face the flower buds upward, wrap them well with packaging paper, and pack them into cardboard boxes for market.