The Calathea Medallion, with its striking foliage, has become a favored houseplant for many enthusiasts. Its large, round leaves display intricate patterns of deep green, light green, and sometimes hints of pink or white on their upper surfaces, complemented by vibrant burgundy undersides. This captivating movement makes it a dynamic addition to any indoor space.
Understanding Your Calathea Medallion
The Calathea Medallion, scientifically known as Goeppertia roseopicta or Calathea roseopicta, originates from the tropical rainforests of Brazil and Ecuador. Its natural habitat provides context for its specific care requirements, as these environments are warm, humid, and offer dappled light beneath a dense canopy. The plant’s distinctive leaf movement, where leaves rise at night and lower during the day, is a phenomenon called nyctinasty, a circadian rhythm response to light cycles. This behavior helps the plant conserve moisture and protect its leaves in its native environment.
Optimal Growing Conditions
Light Needs
Calathea Medallion plants thrive in bright, indirect light, mimicking the filtered light they receive on the rainforest floor. Placing them near a north or east-facing window provides gentle morning light without harsh direct sun. Direct sunlight can scorch the delicate leaves, leading to fading patterns or a burnt appearance. Conversely, insufficient light might cause the vibrant leaf patterns to dull or fade over time.
Watering Practices
Consistent moisture is important for Calathea Medallion plants, but they should never sit in waterlogged soil. Water when the top inch or two of soil feels dry to the touch. Thoroughly watering until water drains from the pot’s bottom ensures the entire root ball receives moisture. Excess water should be emptied from the saucer to prevent root rot.
These plants are particularly sensitive to chemicals found in tap water, such as chlorine and fluoride, which can cause leaf browning. Using filtered, distilled, or rainwater is preferred for watering. Using room temperature water helps avoid shocking the plant’s roots. Watering frequency may need adjustment based on seasonal changes, with more frequent watering in warmer months and less in winter.
Humidity Requirements
High humidity levels are important for Calathea Medallion plants, ideally between 50% to 90%. Their tropical origin means they suffer in dry air, often leading to crispy leaf edges. Methods to increase ambient humidity include using a humidifier, placing the plant on a pebble tray filled with water, or grouping plants together to create a microclimate. While misting can provide temporary relief, it often does not supply sufficient long-term humidity.
Temperature Range
Calathea Medallion plants prefer warm, stable temperatures, ranging from 65°F to 80°F (18°C to 27°C). They are sensitive to cold, and temperatures below 60°F (15°C) can cause damage. It is important to shield them from cold drafts, sudden temperature fluctuations, and direct heat sources like radiators or vents. Consistent temperatures help prevent stress and support healthy growth.
Ideal Soil Mix
A well-draining, moisture-retentive soil mix is suitable for Calathea Medallion plants. An ideal blend includes components like peat moss or coco coir for moisture retention, combined with perlite or coarse sand for drainage and aeration. Some mixes also incorporate small amounts of bark or charcoal to enhance drainage and mimic their natural forest environment. The soil pH should be slightly acidic, between 5.5 and 6.5.
Fertilization Schedule
During the active growing season (spring through early fall), Calathea Medallion plants benefit from regular fertilization. A balanced, water-soluble houseplant fertilizer, diluted to half strength, is recommended. Fertilizing every two to four weeks during this period can provide necessary nutrients. It is best to avoid fertilizing in the winter months when the plant’s growth slows.
Ongoing Plant Maintenance
When and How to Repot
Calathea Medallion plants require repotting every one to two years, or when they show signs of being root-bound. Indications that repotting is necessary include roots emerging from drainage holes or stunted growth. The best time to repot is during the spring or summer growing season, which minimizes stress and allows the plant to acclimate quickly. When repotting, choose a new pot that is only slightly larger, about one to two inches wider than the current one, to avoid overpotting.
Carefully remove the plant from its old pot, being gentle with the root ball. Place it in the new pot, ensuring the top of the root ball is level with the rim, and fill with fresh, appropriate potting mix.
Water the plant thoroughly after repotting to help settle the soil around the roots. Placing the plant in a shaded spot for a week or two post-repotting can aid recovery.
Pruning for Health
Extensive pruning is not needed for Calathea Medallion plants, as their growth habit is upright and bushy. The main purpose of pruning is to remove any yellowed, brown, or dead leaves. This practice helps the plant redirect its energy towards new, healthy growth and maintains its attractive appearance. When removing leaves, make clean cuts close to the base of the stem using sharp, sterilized scissors or pruners.
Troubleshooting Common Problems
Browning or Crispy Leaves
Browning or crispy leaf edges often indicate insufficient humidity, underwatering, or sensitivity to unfiltered tap water. Increase humidity, adjust watering to keep soil consistently moist, and use filtered water if tap water is suspected.
Curling Leaves
Curling leaves are a sign of dehydration, often due to underwatering, low humidity, or exposure to cold temperatures and drafts. Ensure consistent soil moisture, adequate humidity, and protect the plant from cold.
Yellowing Leaves
Yellowing leaves can indicate overwatering, insufficient light, or nutrient deficiency. It can also be a natural part of aging. Address overwatering by allowing soil to dry and ensuring drainage. Provide brighter, indirect light, and consider a balanced liquid fertilizer during the growing season if nutrient deficiency is suspected.
Pest Management
Calathea Medallion plants can attract common houseplant pests like spider mites, mealybugs, and aphids. Isolate affected plants to prevent spread. Wipe leaves with a damp cloth to remove pests, or use insecticidal soap or neem oil solutions. Regular inspection aids early detection.