Seed
Collect seed pods when the tops split open. Separate the chaff and sow immediately. Cultivars may not come true. Plants often take several years to reach flowering age.
Using a deep pot sow thinly, covering with a layer of fine grit. Some seed will germinate straight away, sending up a shoot, (referred to as epigeal) but some lilies will germinate growing roots, with leaves emerging the following spring following a cold spell (referred to as hypogeal). Keep the seed from drying out and wait for the seedlings to appear.
Division
Offsets
are produced around the base of the bulb or near the base
of the old flowering stem on some lilies. These can be removed
in autumn. Bulblets can be potted up at twice their depth.
Flowers should be produced after two to four years.
Bulbils
Bulbils
can be found in the leaf axils of lilies such as L.
bulbiferum, L. leichtinii, L.
sargentiae. When ripe these detach easily and can be
pressed into the surface of a pan of compost. Cover with 13mm
(0.5in) of course sand or fine grit. Keep frost free over
winter, and plant out the following autumn.
Scales
Lift and clean a mature bulb in late summer. Discard any damaged outer scales. Snap off a few scales from the bulb as close as possible to the base. Place in a plastic bag with a 50:50 mix of slightly damp peat substitute and perlite. Shake the bag and fill with air before sealing and labeling. Place in a warm (21°C/70°F), dark place for six weeks. Some lilies such as Lilium martagon need a further six weeks at 5°C (41°F).
When bulblets appear at the base of the scales, pot on individually, covered with their own depth of compost. Do not remove the scale if it has roots coming from the base.
Compost
A mix of equal quantities of John Innes No 3 and an ericaceous multi-purpose compost with additional sharp sand is sufficiently acidic for most lilies.