Cannas grow large, tropical-looking leaves.
Large tropical leaves and colorful blooms make cannas a favored choice. Just a few plants is all it takes to make a splash in an otherwise drab landscape. Because of their upright growth habit, cannas also make a large impact in a small garden. To make the most of your cannas, adopt a regular fertilizing program to keep them blooming from late spring or summer until fall.
Mix in 1/3 cup of 10-10-10 granular fertilizer into the excavated soil of each hole at planting time. Then, plant the cannas and lightly pack the fertilized soil around the rhizomes.
Fertilize cannas each month from spring to fall, stopping about six weeks before the first anticipated fall frost. How much fertilizer depends on the percentage of nitrogen -- the first number in the N-P-K ratio. For example, apply 1/4 pound of 10-10-10 fertilizer for every 25 square feet. If the fertilizer is rated 5-10-10, apply 1/2 cup for every 25 square feet.
Broadcast the fertilizer with your hands, applying it evenly among the plants. Avoid getting the fertilizer on the cannas' foliage or flowers.
Water cannas after each fertilizer application with about 1 inch of water. Alternatively, fertilize cannas the day before an expected rainfall.
Maximize the bloom-boosting benefits of fertilizing by removing or deadheading individual flowers as they fade.
Lewis, Melissa. "How to Fertilize Cannas." Home Guides | SF Gate, http://homeguides.sfgate.com/fertilize-cannas-22632.html. Accessed 24 April 2019.