How To: Growing Corms in Sphagnum Moss

Growing corms in sphagnum moss is an excellent method for propagating plants, especially for species like Alocasias, Caladiums, and certain orchids. This technique provides a well-aerated and moisture-retentive environment that promotes healthy root development and minimizes the risk of rot. Whether you're a beginner or an experienced plant enthusiast, this step-by-step guide will help you successfully grow your own corms using sphagnum moss the way Ryan does.  




What You’ll Need:

  • Healthy corms (from Alocasia, Caladium, etc.)

  • Sphagnum moss (preferably long-fibered, high-quality)

  • A shallow container or propagation box (We use clear 3oz or 5oz cups and tape two together to create a humidity dome) 

  • A spray bottle with distilled or filtered water

  • A plastic bag or humidity dome (optional)

  • A warm, bright location (indirect light)

Step 1: Preparing the Sphagnum Moss

Start by soaking the sphagnum moss in water for about 15–20 minutes until it is fully hydrated.  We add 1 tablespoon of Clonex to a gallon of water when soaking moss for cuttings or corms. Then, squeeze out the excess water so the moss is damp but not dripping. This balance is crucial to prevent the corms from rotting due to excessive moisture.

Step 2: Placing the Corms

Take your healthy corms and gently clean off any excess soil. Inspect them for signs of rot or damage, discarding any that appear unhealthy. Place the corms on top of the damp sphagnum moss, ensuring they are not buried too deep. Lightly cover them with a thin layer of moss, allowing airflow while maintaining moisture.

Step 3: Creating the Ideal Environment

Place the container in a warm, bright area with indirect light. A temperature range of 70–80°F (21–27°C) is ideal for optimal growth. If you live in a dry climate, consider using a plastic bag or humidity dome to maintain high humidity levels, which encourage faster sprouting.  We put our cups inside clear bins that sit on top of a heat mat with a thermostat set at 70°F.  There is a full spectrum grow light mounted to the underside of the shelf above the bin.  These aren't required to be successful, it's just our method.

Step 4: Monitoring and Maintenance

Check the moss regularly to ensure it stays evenly moist but not soggy. If it starts to dry out, lightly mist it with your spray bottle. Avoid overwatering, as excessive moisture can lead to rot. After a few weeks, you should notice small roots and shoots emerging from the corms.

Step 5: Transplanting the Sprouted Corms

Once the corms have developed a healthy root system and their first leaves, they are ready to be transplanted into soil. Use a well-draining potting mix and a container with drainage holes to support continued growth. Gradually acclimate them to their new environment by maintaining consistent moisture and humidity levels.

Tips for Success:

  • Use high-quality sphagnum moss to prevent contamination and improve aeration.

  • Keep the moss moist but never waterlogged.

  • Ensure proper airflow around the corms to prevent fungal issues.

  • Be patient—some corms may take longer to sprout than others.

Growing corms in sphagnum moss is a rewarding propagation method that allows you to expand your plant collection with ease. With the right conditions and care, you’ll be able to successfully cultivate new plants and enjoy the process of nurturing them from the very start!