The elegant and widely-grown calla lily, found in a variety of colours, can be established in gardens or cultivated in containers. If a calla lily has diminished blooms or entirely fails to produce flowers, there are a few possible reasons.
Too much nitrogen, generally resulting from overfertilization, will cause plant foliage to grow well, but may inhibit flower development. Brown edges may also appear on the leaves. Once established, callas should receive low-nitrogen fertiliser every two to three weeks.
Calla lilies may not bloom if they are crowded, whether in a container or planted in the ground. Lift the clump of rhizomes from the soil, separate them, and place them back in the soil at least 6 inches apart and 2 inches deep.
A calla may fail to bloom if the plant receives too little water. The plant will begin to turn yellow, growth will be stunted, and the calla may wilt. Either transplant the lily or provide supplemental water. Callas also prefer locations in full sun.
If the calla lily is planted in a container and does not experience the natural seasons, the lily must undergo a period of dormancy to induce flowering. Stop watering the plant (allow the foliage to die back), and place the calla in a cool, dark place for two months. After this period, resume watering and bring the plant back into light.