My lilies have flowered beautifully for several years but for the last two years flowers have become sparse. My lilies have flowered beautifully for several years but for the last two years flowers have become sparse.
Lilies continually produce new bulbs, from which grow new plants.
As the clump of lilies grows bigger the plants at the center become less productive. The solution is to dig up and divide the crowded clumps every four years or so, in the fall. Take the opportunity to dig in some fresh low-nitrogen fertilizer, such as bone meal. Replant the bulbs growing at the edges of the clump, one to two feet apart, and discard the old bulbs from the center. A healthy vigorous rose is much more likely to get through the winter unscathed than is a stressed or diseased plant.