Producing Plants From Scales
The easiest and most widely used method of increasing lilies is to propagate from the scales that make up the bulb. Flowering plants are produced from these scales in two or three years.
A bulb can be scaled at any time. Use only plump, healthy bulbs, because damaged or infected scales either will not produce new bulbs or will make new bulbs that do not grow properly. If the bulb that is used to supply scales has a virus disease, the new bulbs will have it too.
Remove any withered or damaged scales and discard them. Separate the plump, healthy scales by breaking them off as close to the base as possible, taking a bit of the basal plate with the scale. If only a few new bulbs are wanted, take two or three scales. If you want to develop a number of a given variety, a bulb can be scaled completely, leaving only its heart. Some varieties, however, do not produce good bulbs from scales. If you use a valuable lily, try just a few scales the first time. If you are successful with that bulb, it can be scaled again.
Wash the scales thoroughly; let them dry for several hours or overnight. Place the scales in a plastic bag with enough slightly moist peat moss to keep them separate. Add a pinch of fungicide, such as Benomyl or Captan. Seal the bag and label with the name of the variety and the date.
Put the bag in a warm place, such as a cupboard or closet. Check the bag every week or two to see that the moisture is maintained. If the scales show signs of mildew or other fungus, wash them and rebag.
In 8 to 10 weeks the miniature bulbs, called bulbils, should be formed along the bottom edge of the scale. When the bulbils reach a quarter of an inch or more in diameter, they should be chilled in your refrigerator at about 4 C for six to eight weeks. The original bag with scales can be refrigerated for the cooling period, or the bulbils can be separated and put into a fresh bag with moistened peat moss and fungicide. Check the temperature in various sections of your refrigerator to determine the best location.
Early in the spring, place each new plant in a 2½ to 3 in. pot. Sink the pots in sand or peat moss outdoors. Cover with 1 in. of sand. These can be put permanently in your garden at the end of the summer.Growing Lilies From Seeds
Sowing seeds is a good way to produce a large collection of lilies. Virus disease is not transmitted through the seeds; therefore, you can use this method to produce disease-free lilies for your garden. Such bulbs will also save you considerable money.
After the lily plant has finished blooming, deadhead the faded blooms all but one. Leaving only one pod to form seeds is less taxing on the plant and allows the plant to produce seeds and feed the bulb at the same time. When the pod has turned plump and dark yellow, pinch the pod off and bring indoors. When the pod is dry, it will open and the seeds can be then removed.
Hybrid seeds will not produce plants identical to the parents, but most of the seedlings will be attractive, and there is always the chance that a new lily of superior quality will show up. Flowers first appear the second or third season after sowing, but plants take a year or two more to attain full bloom.
Seeds can be sown immediately after harvesting or in the spring. Young lily seedlings are susceptible to soil-borne fungi and should be grown in a sterile soil during the early stages of development.
Using pots or trays, sow the seeds an inch apart, covering them with about half an inch of soil.
A cool greenhouse (or a windowsill that has some sun for part of the day) is a good location. A temperature range of 13 - 24 C is best. Seeds germinate faster at warmer temperatures. A steady supply of moisture and nutrients is essential, as is good drainage.
Seeds can be started at any time of the year indoors, and fluorescent lighting can be used with excellent results. Set the lights 2-3 inches above the flats; then raise the lights or lower the flats as the seedlings grow, always maintaining the same distance. When the seeds have germinated, give them from 14 to 16 hours of light per day.
Seedlings with bulbs more than half an inch in diameter and good roots can be put into the open garden at the end of the first season, or they can be grown in a 3 to 4 inch pot for another year before being set out.
The above information comes from Lilies In The Valley.
Further information on growing lilies from seed can be found here.