When to Take a Potted Calla Lily Out of Hibernation?

Dormant Period

• Calla lilies usually go dormant around the time of the first frost if they are grown outdoors, or you can force dormancy indoors by stopping watering and moving the plants to a cool, dark area. Although the plants don't require a long dormant period, they are typically left in storage until late winter or spring. Remove the containers from storage about six weeks before the last expected spring frost so you can induce growth indoors. The calla will be almost ready to bloom when you move it outdoors six weeks later.

Repotting

• Repotting into a container one size larger than the old pot makes room for the growing root system. Repot the calla after you take it from winter storage but before new growth begins. Pots must have a bottom drainage hole so excess moisture doesn't collect in the container. Use any standard houseplant potting soil as long as it drains well without drying out too quickly. When replanting the calla roots, set them in the pot with the tops 3 to 4 inches beneath the soil surface. Grow only one calla per container.

Early Care

• The callas only require water and sunlight to force them out of dormancy. Water when the top 1 inch of soil begins to dry, watering until the excess moisture drips from the bottom of the pot. Empty the collected water from the drip tray afterward. Provide the calla lily with bright but indirect sunlight throughout the day. You can move the plants outdoors to a shaded area after frost danger has passed and nighttime temperatures are above 55 degrees Fahrenheit.

Semi-Dormancy

• A dormancy period isn't necessary, although the calla does benefit from the rest. If you prefer plants to remain green year around, or if you don't have a suitable storage space, you can keep the calla semi-dormant. Placing the pot near an indoor window so it receives bright, indirect light all winter long keeps the foliage green. Maintain temperatures above 55 degrees so the plant isn't damaged or forced into dormancy. Winter-grown callas don't require fertilization, but they do need water when the top 1 inch of of soil dries.