Growing Cannas Commercially
Cannas make a dramatic statement in the landscape due to their large, bold colored blooms and lush tropical foliage. Whether used as a backdrop in your perennial border or as a focal point in large containers, cannas will provide your customer with color from early in the season until frost.
When to Plant:
Cannas can be planted anytime of year in USDA zones 9 and 10, but preferably soil temperature should be 55° to 65°. In the cooler zones 3-8, plant in spring and summer (when ground temperature is not below 55° to 65°). They can be started inside a greenhouse one month before moving them outside.
Where to Plant:
Plant in a sunny location with plenty of moisture and fertility for optimum growth. The soil pH isn’t critical.
How to Plant:
Landscape – Prepare soil by spading and adding compost or rotted manure. Plant rhizomes 1 1/2″ deep and spaced 18″-24″ apart. Soak well after planting. Cannas prefer a lot of moisture and thrive in a very humid environment.
Container – Pot one rhizome (2-3 eye) per gallon in well drained potting mix. Media pH and soluble salt levels are not critical.
Fertilize established (2-3 weeks) plants monthly, with 1:2:1 ratio (12:24:12 or 5:10:5), fertilizing at 1/2 the package recommendation, and water well. NPK at 200 ppm weekly in injector fed systems.
The only insect pest of consequence affecting cannas is the moth larva, commonly called a “leaf roller worm” (primarily a problem in the south). It can be controlled with application of malathion every three weeks.
Containers will typically finish in 10-12 weeks when potted during the appropriate temperatures: day 70-75°F and night 55-65°F.
In zones 3-7, landscape cannas should be dug after the first light frost in the fall and stored at 45-50°F, though success varies greatly from cultivar to cultivar. Zones 8-10 should mulch before heavy frost. Container plants need appropriate winter protection for the area.