Canna ‘City of Portland’ is a popular ornamental plant, cherished for its vibrant presence and distinctive flowers. Its tropical allure brings a splash of color to any garden setting.
Understanding Canna City of Portland
Canna ‘City of Portland’ produces abundant, showy, coral-pink flowers on tall, branching stalks from mid-summer into fall. The flowers are salmon-pink or light orange, sometimes resembling the color of watermelon. Its lush, lance-shaped leaves are typically green, though some descriptions note a red-edged, mid-to-dark green foliage. This canna lily reaches a mature height of 4 to 6 feet (120-180 cm), with a spread of 1 to 3 feet (30-90 cm).
This canna is a tender perennial, generally hardy in USDA Zones 8 through 11, where it can remain in the ground year-round. In colder climates, it is grown as an annual or its rhizomes are overwintered indoors. ‘City of Portland’ is well-suited for mass plantings, as a focal point in garden beds, or for container growing on patios. It attracts butterflies, hummingbirds, and bees, and is deer and rabbit resistant.
Planting and Growing Canna City of Portland
Canna ‘City of Portland’ thrives in full sun, requiring at least six to eight hours of direct sunlight daily for optimal growth and flowering. A sheltered location can also be beneficial, especially in areas prone to strong winds.
The ideal soil for ‘City of Portland’ is organically rich, moist, and well-drained. It tolerates a wide range of soil pH, from acidic to alkaline, with a preferred range of 6.0 to 7.5. When planting rhizomes, place them 2 to 3 inches deep and 12 to 24 inches apart to allow for proper growth and spread. For container-grown plants, ensure the pot is adequately sized to accommodate the plant’s mature height and spread.
Consistent moisture is crucial for ‘City of Portland’ cannas, especially during dry periods and hot weather. Keep soil moist but not waterlogged to prevent rot. Cannas are heavy feeders, benefiting from regular fertilization to support their vigorous growth and prolific blooming. Apply a balanced, slow-release fertilizer at planting, then a high-phosphorus, water-soluble fertilizer every 4 to 6 weeks during the growing season. Incorporating organic matter like composted manure also provides significant benefits.
Deadheading spent blooms encourages continuous flowering by redirecting the plant’s energy from seed production to new flower development. Snip the spent bloom just below the flower head; avoid cutting further down the stalk as new blooms may be developing. Staking may be necessary for taller plants, especially in windy conditions, to prevent the stems from bending or breaking.
Winterizing Canna City of Portland
For gardeners in regions colder than USDA Zone 8, Canna ‘City of Portland’ rhizomes need to be lifted and stored indoors for winter. Do this in fall, after the first light frost kills the foliage but before the ground freezes, signaling dormancy.
To prepare the rhizomes, gently dig them from the ground, removing as much soil as possible. Cut back the foliage to 2 to 3 inches from the top. Air-dry them in a warm, dry, well-ventilated area for about a week to toughen their outer skins and reduce rot risk during storage.
Store cleaned and cured rhizomes in a cool, dark, and dry location above 40°F (4-7°C), such as a basement or unheated garage. Place them in cardboard boxes or paper bags, possibly with a small amount of dry peat moss or vermiculite to absorb excess moisture and prevent contact between rhizomes. Avoid plastic bags, as they can trap moisture and lead to mold or rot. Check rhizomes periodically for any signs of shriveling or mold, adjusting moisture levels or air circulation as needed. Replant the rhizomes in spring after frost danger passes and soil warms.
Addressing Common Issues
Canna ‘City of Portland’ can encounter certain issues. Pests such as canna leaf rollers, Japanese beetles, caterpillars, slugs, and snails may occasionally feed on the foliage or chew holes. For minor infestations, hand-picking is effective. Spider mites and aphids are also common, particularly in greenhouse settings, and can cause yellowing or damage to leaves.
Regarding diseases, canna rust and canna mosaic virus are potential concerns. Canna rust appears as yellow spore-producing structures on the underside of leaves and tan spots on the upper side. Promptly removing and discarding affected leaves can help prevent the spread of rust. Canna mosaic virus, often spread by aphids, can cause leaf deformities, mottling, or streaking. Maintaining good garden hygiene, such as cleaning gardening tools, can help prevent the spread of viral diseases.
Environmental stress can also manifest in the plant’s appearance. Yellowing leaves might indicate issues with watering, either too much or too little, or a nutrient deficiency. Ensuring consistent moisture and proper fertilization helps prevent these problems. A lack of blooms can often be attributed to insufficient sunlight or inadequate nutrients, underscoring the importance of planting in full sun and adhering to a regular feeding schedule.