Calla lilies are typically not cold-hardy and can be sensitive to freezing temperatures. If your lilies are looking sick as the winter starts to get colder, it's possible that they are experiencing damage from the cold.

Here are some steps you can take to help your Calla lilies survive the cold:

Protect the plants from frost: Cover the lilies with frost cloth or burlap to protect them from frost. This will help to keep the plants warm and prevent damage from freezing temperatures.

Move the plants indoors: If possible, move the plants indoors to a warm and bright location. This will help to protect them from the cold and provide them with the light they need to survive.

Provide extra insulation: Add extra insulation around the roots of the plants. You can do this by adding a layer of mulch or straw around the base of the plants. This will help to protect the roots from freezing temperatures.

Reduce watering: During the winter, the lilies will not need as much water as they do during the growing season. Reduce watering to prevent the roots from becoming waterlogged and potentially freezing.

Prune damaged foliage: If the plants have already experienced damage, prune back any damaged or dead foliage. This will help to redirect the plant's energy to healthy growth.

With these steps, you can help your Calla lilies survive the winter and thrive in the spring.