How to Winterize Calla Lilies and Arum Lilies: A Comprehensive Guide

Introduction

Calla lilies (Zantedeschia spp.) and Arum lilies (Zantedeschia aethiopica) are beloved for their elegant and striking blooms. However, these plants are not frost-hardy and require special care during the winter months to ensure they survive and thrive in the following growing season. This comprehensive guide provides detailed instructions on how to winterize Calla and Arum lilies, incorporating insights from various expert sources.

Understanding Winterizing Needs

Why Winterizing is Important

Calla and Arum lilies are native to warmer climates and are not naturally equipped to handle freezing temperatures. Winterizing these plants helps to protect their bulbs from frost damage and ensures that they can re-emerge healthy and vibrant in the spring.

Steps to Winterize Calla and Arum Lilies

1. Preparing the Lilies for Winter

• Stop Watering: As the growing season ends and the leaves start to yellow, gradually reduce watering. This helps the plant to enter dormancy.
• Prune the Foliage: Once the foliage has completely yellowed and died back, cut it down to a few inches above the ground. This helps to prevent rot and disease during storage.

2. Digging Up the Bulbs

• Careful Digging: Use a garden fork or spade to gently lift the bulbs from the ground. Be careful not to damage them as wounds can become entry points for disease.
• Cleaning the Bulbs: Brush off any excess soil from the bulbs. Do not wash them with water as moisture can promote rot during storage.

3. Drying the Bulbs

• Air Drying: Place the bulbs in a dry, cool area with good air circulation for a few days to cure. This process helps to harden the outer skin and reduces the risk of mold and rot.

Storing the Bulbs

4. Preparing for Storage

• Storage Medium: Pack the dried bulbs in a breathable medium such as peat moss, vermiculite, or sawdust. This helps to absorb any excess moisture and keeps the bulbs dry.
• Container Selection: Store the bulbs in a cardboard box, paper bag, or mesh bag. Avoid using plastic bags as they can trap moisture and promote rot.

5. Choosing the Right Storage Location

• Cool and Dark: Store the packed bulbs in a cool, dark place with temperatures between 5-10°C (41-50°F). A basement, garage, or unheated closet can be ideal.
• Regular Inspection: Check the bulbs periodically throughout the winter for signs of rot or mold. Remove any affected bulbs immediately to prevent the spread of disease.

Winter Care for Potted Lilies

6. Indoor Overwintering

• Bring Indoors: If you have Calla or Arum lilies in pots, bring them indoors before the first frost. Place them in a cool, dry area where they can remain dormant.
• Minimal Watering: Water sparingly throughout the winter. The goal is to keep the soil just barely moist to prevent the bulbs from drying out completely.

Replanting in Spring

7. Preparing for Replanting

• Inspect the Bulbs: Before replanting, inspect the bulbs for any signs of damage or disease. Discard any that appear unhealthy.
• Soil Preparation: Prepare your garden bed or pots with fresh, well-draining soil enriched with organic matter.

8. Replanting the Bulbs

• Timing: Plant the bulbs in spring after the danger of frost has passed and the soil has warmed.
• Planting Depth and Spacing: Plant the bulbs about 5-10 cm deep and space them 30-40 cm apart to allow for healthy growth and air circulation.

Conclusion

Winterizing Calla and Arum lilies is a crucial step in ensuring their survival and vigor for the next growing season. By following these detailed steps for digging up, drying, storing, and replanting the bulbs, you can enjoy their stunning blooms year after year. Proper winter care helps protect these delicate plants from the harsh conditions of winter, allowing them to thrive once the warmth of spring returns.

By adhering to these guidelines, you can ensure that your Calla and Arum lilies remain healthy and vibrant, ready to burst into bloom with the return of warmer weather.