The Average Blooms Per Calla Lily Bulb

Rhizome Anatomy

• Each calla lily rhizome has several growing points, or eyes. Stems and flowers grow directly from the eyes. In general, a large rhizome produces more flowers than a small rhizome, but bloom quantities also are determined by cultivar. For example, small calla lily cultivars produce up to 25 flowers per rhizome, and tall calla lily cultivars may produce about 10 flowers per rhizome. That is because a small cultivar's rhizome does not need to expend as much energy on plant growth as a taller cultivar's rhizome, and so more of a small cultivar's energy is directed to flower production.

Moisture and Soil

• If you plant calla lily rhizomes with the eyes pointing downward, the bloom quantities suffer because the plants' leaves cannot reach the sunlight needed for photosynthesis. The rhizomes should be planted with the majority of growing points facing the sky. Cultivate your planting area with organic material to maintain a well-drained site. Rhizomes succumb to rot and failed flowering if they are subjected to wet conditions. Friable soil and moist conditions encourage vigorous rhizome growth and flower development. Because they are perennials, calla lilies consistently flower each year if they are planted properly.

Sunlight

• As your calla lilies produce dense leaf clusters, they harness the sunlight's energy for rhizome growth. In fact, their bloom quantities increase over time because the rhizomes use the energy produced in the leaves to spread farther and produce multiple growing points. The flowers may fail in hot planting locations, however. Encourage successful flowering by placing your calla lilies in a position that receives partial sunlight. For example, expose the lilies to morning sunlight while providing shade from afternoon heat. The leaves take advantage of the early light while protected from heat-stress later in the day.

Preparation for Next Year

• Although calla lilies blossom for as long as two months, their rhizomes must rest between seasons to collect enough energy for future flowering. As your lilies' leaves fade, do not cut them off. Allow the foliage to yellow and die back naturally so the rhizomes can benefit from the stored energy generated through photosynthesis. If you cut the leaves back while they are still green, future flowering decreases in quantity; the rhizomes will not have enough energy to produce as many flowers, and they may be smaller than normal in size as well.