Planting and Care of Bulbs: Spread
Plant enough bulbs for a showy display. For best appearance, plant bulbs in masses - usually in groups of 3 or more. Space bulbs in beds according to the size of the bulb. As a general rule, large bulbs, such as our Bulb-Zilla lily bulbs should be spaced 6 to 8 inches apart. They will quickly spread and fill this space in no time. Lilies will gradually increase (naturalize) by division of the large main bulbs and by growth of small bulbs along the old below-ground stem. Species lilies and tiger lilies will spread more than Oriental and Hybrid lilies and form large clumps throughout a garden bed.
Which End Is Up?