Canna lilies are striking tropical plants known for their vibrant flowers and bold foliage. These rhizomatous perennials, related to bananas and ginger, are typically grown outdoors. With proper care, however, they can flourish indoors, bringing a touch of the tropics to your home. Growing cannas indoors requires specific considerations, but the reward is a continuous display of lush greenery and colorful blooms.
Getting Started with Indoor Canna Lilies
Cultivating canna lilies indoors begins with careful selection and planting. Compact or dwarf varieties are best suited for indoor environments, as larger types can exceed 6 feet. When choosing rhizomes, look for firm, healthy pieces with multiple “eyes” or buds, which indicate future growth. Avoid shriveled or mushy rhizomes, as they may be rotted.
Select a container at least 12 inches in diameter, or 15-18 inches for larger growth, ensuring it has drainage holes to prevent waterlogging. Use a rich, well-draining potting mix, amended with compost or perlite. Plant the rhizome 4-6 inches deep with the eyes pointing upwards, firm the soil, and water to settle.
Daily Care for Indoor Canna Lilies
Light
Canna lilies require abundant light to thrive and bloom indoors. They need at least 6 hours of direct sunlight daily, making a south or west-facing window ideal. Place the pot directly in front of the window to maximize light intensity. Insufficient light often leads to a lack of flowers and leggy growth. Supplemental grow lights may be necessary during shorter winter months to ensure consistent light exposure.
Watering
Canna lilies need consistent moisture, as they are accustomed to wet environments. Keep the soil uniformly moist but never soggy, as standing water can cause rhizome rot. Watering frequency varies; check the top 1-2 inches of soil and water when it feels dry. Signs of insufficient water include tearing or cracking leaves, while yellowing leaves can indicate overwatering.
Temperature and Humidity
As tropical plants, canna lilies prefer warm conditions, thriving in temperatures between 60-85°F. Consistent warmth promotes active growth, allowing them to bloom through winter if temperatures stay above 60°F. Cannas also prefer moderate to high humidity, around 40-60%. In dry indoor environments, especially during winter, brown or crispy leaf edges may appear. To increase humidity, place the pot on a pebble tray filled with water or use a room humidifier.
Fertilizing
Canna lilies are “hungry plants” and benefit from regular fertilization during their active growing season. Apply a balanced, slow-release fertilizer in early spring and mid-summer. Alternatively, use a liquid all-purpose fertilizer at half strength during spring/summer and quarter strength in fall/winter if the plant remains active. Reduce or stop fertilization as growth slows in late fall or if dormancy is induced.
Managing Indoor Canna Lily Dormancy
Canna lilies do not require dormancy and can grow year-round indoors with consistent warmth, light, and moisture. However, if conditions become less than ideal, such as reduced light or cooler temperatures, cannas may naturally enter dormancy. Inducing dormancy can also manage plant size or reduce care during colder months.
To induce dormancy, gradually reduce watering in the fall as days shorten. The foliage will yellow and die back. Once top growth withers, cut stems to about 6 inches from the soil. Rhizomes can be stored in their pot or removed.
If storing in the pot, ensure dry soil to prevent rot, and move to a cool, dark location (40-50°F). If removing rhizomes, clean off excess soil, air-dry for several days, and store in dry peat moss, vermiculite, or newspaper in a similar cool, dark, dry environment. Check stored rhizomes periodically for rot or dryness. To reawaken, bring them to a warm spot (around 70°F), plant or re-pot, and begin light watering; sprouts emerge within a few weeks.
Troubleshooting Common Indoor Canna Lily Problems
Indoor canna lilies are robust, but issues can arise. Yellowing leaves often indicate overwatering or insufficient light. Consistently wet soil with yellowing leaves suggests overwatering, potentially leading to root or rhizome rot. Pale green or yellowing leaves with leggy growth point to inadequate sunlight. Adjusting watering and light exposure can resolve these issues.
A lack of blooms, despite healthy foliage, is due to insufficient light. Cannas require direct sunlight to flower, so relocate the plant or use grow lights. Overcrowding can also inhibit flowering.
Common indoor pests include spider mites, aphids, and mealybugs. Spider mites thrive in dry conditions, causing speckled yellowing and webbing. Aphids cluster on new growth, leading to distorted leaves and honeydew. Mealybugs appear as white, cottony spots. Regular inspection and timely treatment with insecticidal soap or neem oil manage these pests.
Fungal diseases like leaf spot or root rot can occur, linked to high humidity, poor air circulation, or persistent overwatering. Good air circulation and appropriate watering are preventive measures.