Last year I planted calla lilies in the ground, and they bloomed beautifully. I overwintered the bulbs in the basement over the winter, and planted them outside this spring. I had lovely foliage, but no blossoms. I had split them up and planted them in two separate locations, but neither group bloomed. Any ideas how I can get them to bloom next year?
Thank you for contacting Toronto Master Gardeners
The Calla Lilly, Zantedeschia aethiopica, originally comes from tropical marshes. Several factors can play a role in the success of this plant and its ability to flower.
For these plants to develop flowers they need to be very well hydrated. As they are used to growing in swamps they will not be happy drying out. The rhizome (bulb) needs to be planted in an area that is well drained to avoid rot, but is well hydrated. In our climate, one would need to water the plant very regularly and monitor its hydration. With the summer we just had it would have been difficult to keep them hydrated enough.
Another key factor is nitrogen. If the plant has too much nitrogen available it will be encouraged to grow green leaves and not flowers. Are the bulbs planted near lawn that is fertilized? If so, grass fertilizer is very high in nitrogen and may have landed near your plants.
The last factor is light levels. The Calla lily needs ample light levels. If it is shady it may not develop flowers. They are thrive in direct full sun. Has anything changed in nearby in your garden that may have changed the light levels?
Taking care of these key factors should help you with encouraging your calla lilies to bloom in the future.
I have attached a link for you for further reading. Good luck.