Cannas bulbs are successfully grown in nutrient-rich soil and full sun. They can be grown in large containers indoors or outdoors in a garden. The materials needed to grow cannas bulbs include a shovel, soil, and sometimes fertilizer and mulch. If growing indoors, availability of space can be an issue because cannas do not tend to thrive in overcrowded spaces. This is also holds true when planting outdoors, and in this case, a plan should be designed allowing for the plant’s needed space between itself and other species in a garden.
In the garden, select a spot that is full-sun and is well-drained with rich soil full of organic humus, which can be turned to provide loose soil for the cannas bulbs to be planted. When growing the plants from multiple bulbs of a larger variety, plant the bulbs 12 to 18 inches (30.48 to 45.72 cm) apart, as each bulb will produce new bulbs as it grows to maturation. For better results, the eye of the bulb should be facing upwards as the bulb is planted, but even bulbs planted horizontally still have a good chance of maturing. How deep in the ground the bulbs are planted depends on where the garden is in relation to the equator, as the closer the garden is, the deeper the bulbs can be planted. In warmer-temperate and tropical areas, cannas can be planted 6 to 8 inches (15.24 to 20.32 cm) deep and stay in the ground year-round, but in colder climates, the bulbs need to be planted in shallow trenches so they can be easily removed for the winter.
Add water and fertilizer to the cannas bulb when planting and gently tamp the ground around the bulb. At this point, an optional groundcover of mulch, 1- to 2-inches-wide (2.54 to 5.08 cm), can help the soil retain the majority of its moisture, as cannas grow best in wet conditions because of their tropical nature. Water the cannas bulbs once a week, soaking them completely. During the growing season, fertilize once a month to help maintain longer blooms.
The cannas plant is often grown for its bright and colorful flowers and lush, fan-like leaves, which tend to be colorful in variegated species. To maintain the best foliage, do not let the soil dry out for more than two days in a row. If the bulbs are to be harvested, they should be collected before the first frost, as they are sensitive to the cold.