It is difficult to document the lineages of the countless modern garden varieties that have been hybridized from ten species of Canna. Straight species that are popularly grown within their native ranges are rare here. Some species are grown for their thick edible rhizomes. Many are grown for edible foliage. Some are employed to absorb toxins from contaminated riparian environments.
Garden varieties that are popular here are grown merely for their aesthetic appeal. The lushly big leaves are typically rich green, but might be bronzed, dark purplish bronze, or striped with yellow, bronze, creamy white or peachy pink. Large varieties get taller than eight feet. Compact types stay less than three feet tall. All foliage dies to the ground after frost, and grows back fast in spring.
The flashiest parts of canna flowers are actually very specialized stamens known as staminodes, which mostly obscure the very subdued petals and sepals. Red, orange, yellow, pink, salmon or very pale yellowish white bloom may be spotted or blotched. Flowers might be thin and wispy, or rather floppy and lush. Canna are popularly known as canna lilies, but are not at all related to lilies.
Not only does it start to bloom late in summer, but as the name implies, four o’clock, Mirabilis jalapa, blooms late in the afternoon to attract nocturnal moths for pollination overnight. By morning, the white, yellow, variable pink or rarely pastel orange flowers are closed, and their yummy fragrance is gone. Individual flowers often display irregular stripes or blotches of alternate colors, and can be divided into zones that are shaped like slices out of a pizza. Plants get nearly three feet high, but then die to the ground with the first frost. They regenerate from big tuberous roots as winter ends, and can seed profusely.
A flower that is so prominent in American culture should have a more appealing name than black-eyed Susan. Even the Latin name, Rudbeckia hirta, sounds bad. Is Becky really so rude? Did she hirt Susan? Well, black-eyed Susan is good enough to be the state flower of Maryland, and is one of the most popular of flowers for prairie style gardens of the Midwest. After all, it naturally grows wild in every state east of Colorado. Here in the West, it is a light-duty perennial that is more often grown as an annual. As a cut flower, it can last more than a week.
Are warm season annuals really the most colorful flowers for summer? Perhaps. They have their limits though. They are also very demanding. They need to be watered very regularly, and should probably be fertilized too. Many need to be deadheaded frequently. After all that, they are only temporary, and will get replaced with cool season annuals in autumn. Perennials are more practical.
Tony Tomeo 