Bulbs look best when planted in large groups or naturalised in grass and allowed to increase naturally. Bulbs grow naturally once they are planted in the garden and will form clumps. The easiest method of propagation is, therefore, simply to lift an established clump and divide it before replanting.
Lilies take special consideration. A few types of lily bulbs, including tiger lilies, produce small bulbs called bulbils or bulblets at the leaf axils up the stem. One way of propagating lilies to by separating scales from the lily bulbs.
Dig up the Lilies. Stem-rooting lilies produce bulbils underground if they are mulched with a thick layer of loose organic material. The bulbils can be separated when the lily stem dies in autumn. After lilies have gone dormant, it is time to propagate lilies. Using a garden trowel, gently dig around and finally under the dormant lily.
Clean the lilies. Remove any dead stalks and wash the lilies gently under running water. Place the lilies on a cotton cloth to dry.
Take a clean, dormant lily bulb and snap off some of the outside scales, as close to the base as possible. Be careful not to damage the scales as you remove them from the bulb. Each scale of the lily bulb can be separated from an established plant and encouraged to produce one or more bulblets.
Place the scales in a bag of fungicide. Close the bag and gently shake the lilies and fungicide until the lilies are completely coated. Prepare a mixture of equal parts peat and perlite or vermiculite in a plastic storage bag. Each separated piece should produce a new plant.
Dampen the mix. Gently sprinkle water into the bag. Shake the scales free of excess fungicide and place them in a clean plastic storage bag.
Store. The bags need to be stored in a warm, dark place for six to eight weeks and planted when bulblets appear on the scales.
Plan to propagate lilies about two months before planting season.
Make sure to store the bags in a warm, dark but not too damp place or mould may grow on the bulbs.